I am attempting to upgrade a project from 8.9.0 to 8.10.1 and get an error upon rebuild. It doesn’t really give any indication of what I need to fix other than perhaps a custom/plugin widget (since the message mentions PluginWidget a lot), but we are using a few of those – both our own and 3rd party ones, and none of them have a parameter named ‘str’. So I don’t really know where to start. Any help is appreciated. Here is the full error message: System.AggregateException: One or more errors occurred. ---> System.ArgumentNullException: Value cannot be null. Parameter name: str at Mendix.Modeler.WebUI.Util.ObjectExtensions.NotNull[T](T str) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Util\ObjectExtensions.cs:line 10 at Mendix.Modeler.WebUI.Forms.Common.Expressions.ExpressionWriter.WriteVariable(JsonWriter writer, VariableExpr expression) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Common\Expressions\ExpressionWriter.cs:line 73 at System.Collections.Generic.List`1.ForEach(Action`1 action) at Mendix.Modeler.WebUI.Forms.Common.Expressions.ExpressionWriter.WriteFunction(JsonWriter writer, FunctionCallExpr expression) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Common\Expressions\ExpressionWriter.cs:line 63 at Mendix.Modeler.WebUI.Forms.Common.Expressions.ExpressionWriter.WriteConditional(JsonWriter writer, Expr condition, Action`1 thenAction, Action`1 elseAction) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Common\Expressions\ExpressionWriter.cs:line 98 at Mendix.Modeler.WebUI.Forms.Common.Expressions.ParameterisedExpressionWriter.Write(MicroflowExpression expression, JsonWriter writer, IExportContext context) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Common\Expressions\ParameterisedExpressionWriter.cs:line 21 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteProperty(String type, Action`1 paramsWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 49 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Forms.Exporter.FormWriter.GetWidgetProperties(Action`1 writeProperties) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Exporter\FormWriter.cs:line 145 at Mendix.Modeler.WebUI.PluginWidgets.PluginWidget.WriteWidget(IFormWriter formWriter, IWebExportContext context) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\PluginWidgets\PluginWidget.cs:line 53 at Mendix.Modeler.WebUI.Forms.Widgets.EntityWidgets.DataViews.DataView.<>c__DisplayClass65_0.<WriteTemplates>b__0() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\EntityWidgets\DataViews\DataView.cs:line 207 at Mendix.Modeler.WebUI.Forms.Exporter.FormWriter.WriteTemplate(IExportContext context, IDocumentObject documentObject, String templateName, Action writeTemplate) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Exporter\FormWriter.cs:line 134 at Mendix.Modeler.WebUI.Forms.Widgets.EntityWidgets.DataViews.DataView.WriteTemplates(FormWriter formWriter, IWebExportContext context) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\EntityWidgets\DataViews\DataView.cs:line 212 at Mendix.Modeler.WebUI.Forms.Exporter.FormWriter.WriteTemplates() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Exporter\FormWriter.cs:line 84 at Mendix.Modeler.WebUI.Forms.Exporter.FormWriter.Write() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Exporter\FormWriter.cs:line 178 at Mendix.Modeler.WebUI.Forms.Exporter.FormExporter.<>c__DisplayClass7_0.<ExportForms>b__6(<>f__AnonymousType10`3 x) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Exporter\FormExporter.cs:line 85 at System.Linq.Parallel.ForAllOperator`1.ForAllEnumerator`1.MoveNext(TInput& currentElement, Int32& currentKey) at System.Linq.Parallel.ForAllSpoolingTask`2.SpoolingWork() at System.Linq.Parallel.SpoolingTaskBase.Work() at System.Linq.Parallel.QueryTask.BaseWork(Object unused) at System.Threading.Tasks.Task.Execute() --- End of inner exception stack trace --- at System.Linq.Parallel.QueryTaskGroupState.QueryEnd(Boolean userInitiatedDispose) at System.Linq.Parallel.DefaultMergeHelper`2.System.Linq.Parallel.IMergeHelper<TInputOutput>.Execute() at System.Linq.Parallel.MergeExecutor`1.Execute[TKey](PartitionedStream`2 partitions, Boolean ignoreOutput, ParallelMergeOptions options, TaskScheduler taskScheduler, Boolean isOrdered, CancellationState cancellationState, Int32 queryId) at System.Linq.Parallel.PartitionedStreamMerger`1.Receive[TKey](PartitionedStream`2 partitionedStream) at System.Linq.Parallel.ForAllOperator`1.WrapPartitionedStream[TKey](PartitionedStream`2 inputStream, IPartitionedStreamRecipient`1 recipient, Boolean preferStriping, QuerySettings settings) at System.Linq.Parallel.UnaryQueryOperator`2.UnaryQueryOperatorResults.ChildResultsRecipient.Receive[TKey](PartitionedStream`2 inputStream) at System.Linq.Parallel.SelectManyQueryOperator`3.WrapPartitionedStreamNotIndexed[TLeftKey](PartitionedStream`2 inputStream, IPartitionedStreamRecipient`1 recipient, QuerySettings settings) at System.Linq.Parallel.SelectManyQueryOperator`3.WrapPartitionedStream[TLeftKey](PartitionedStream`2 inputStream, IPartitionedStreamRecipient`1 recipient, Boolean preferStriping, QuerySettings settings) at System.Linq.Parallel.UnaryQueryOperator`2.UnaryQueryOperatorResults.ChildResultsRecipient.Receive[TKey](PartitionedStream`2 inputStream) at System.Linq.Parallel.IndexedSelectQueryOperator`2.WrapPartitionedStream[TKey](PartitionedStream`2 inputStream, IPartitionedStreamRecipient`1 recipient, Boolean preferStriping, QuerySettings settings) at System.Linq.Parallel.UnaryQueryOperator`2.UnaryQueryOperatorResults.ChildResultsRecipient.Receive[TKey](PartitionedStream`2 inputStream) at System.Linq.Parallel.ScanQueryOperator`1.ScanEnumerableQueryOperatorResults.GivePartitionedStream(IPartitionedStreamRecipient`1 recipient) at System.Linq.Parallel.UnaryQueryOperator`2.UnaryQueryOperatorResults.GivePartitionedStream(IPartitionedStreamRecipient`1 recipient) at System.Linq.Parallel.UnaryQueryOperator`2.UnaryQueryOperatorResults.GivePartitionedStream(IPartitionedStreamRecipient`1 recipient) at System.Linq.Parallel.UnaryQueryOperator`2.UnaryQueryOperatorResults.GivePartitionedStream(IPartitionedStreamRecipient`1 recipient) at System.Linq.Parallel.QueryOperator`1.GetOpenedEnumerator(Nullable`1 mergeOptions, Boolean suppressOrder, Boolean forEffect, QuerySettings querySettings) at System.Linq.Parallel.ForAllOperator`1.RunSynchronously() at Mendix.Modeler.WebUI.Forms.Exporter.FormExporter.ExportForms(IProject project, Boolean updateRunningProject) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Exporter\FormExporter.cs:line 72 at Mendix.Modeler.WebUI.Deployment.WebUIDeploymentWorker.ExportPages(IProject project, IProgressInfo info, Boolean updateRunningProject) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Deployment\WebUIDeploymentWorker.cs:line 132 at Mendix.Modeler.WebUI.Deployment.WebUIDeploymentWorker.DoWork(DeploymentPhase phase, IProject project, DeploymentSettings settings, IProgressInfo info) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Deployment\WebUIDeploymentWorker.cs:line 82 at Mendix.Modeler.Deployment.DeploymentProcessBuilder.<>c__DisplayClass12_0.<AddBuildStepsForPhase>b__0(IProgressInfo info) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Deployment\DeploymentProcessBuilder.cs:line 124 at Mendix.Modeler.Deployment.FileIOExceptionHandlingProcess.CatchDiskException(Action action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Deployment\FileIOExceptionHandlingProcess.cs:line 28 at Mendix.Modeler.Deployment.FileIOExceptionHandlingProcess.<>c__DisplayClass1_0.<AddStep>b__0(IProgressInfo info) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Deployment\FileIOExceptionHandlingProcess.cs:line 19 at Mendix.Modeler.UIFramework.Progress.ProcessRunner.RunStep(Step step) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.UIFramework\Progress\ProcessRunner.cs:line 83 at Mendix.Modeler.UIFramework.Progress.ProcessRunner.OnDoWork(Object sender, DoWorkEventArgs e) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.UIFramework\Progress\ProcessRunner.cs:line 63 at System.ComponentModel.BackgroundWorker.OnDoWork(DoWorkEventArgs e) at System.ComponentModel.BackgroundWorker.WorkerThreadStart(Object argument) ---> (Inner Exception #0) System.ArgumentNullException: Value cannot be null. Parameter name: str at Mendix.Modeler.WebUI.Util.ObjectExtensions.NotNull[T](T str) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Util\ObjectExtensions.cs:line 10 at Mendix.Modeler.WebUI.Forms.Common.Expressions.ExpressionWriter.WriteVariable(JsonWriter writer, VariableExpr expression) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Common\Expressions\ExpressionWriter.cs:line 73 at System.Collections.Generic.List`1.ForEach(Action`1 action) at Mendix.Modeler.WebUI.Forms.Common.Expressions.ExpressionWriter.WriteFunction(JsonWriter writer, FunctionCallExpr expression) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Common\Expressions\ExpressionWriter.cs:line 63 at Mendix.Modeler.WebUI.Forms.Common.Expressions.ExpressionWriter.WriteConditional(JsonWriter writer, Expr condition, Action`1 thenAction, Action`1 elseAction) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Common\Expressions\ExpressionWriter.cs:line 98 at Mendix.Modeler.WebUI.Forms.Common.Expressions.ParameterisedExpressionWriter.Write(MicroflowExpression expression, JsonWriter writer, IExportContext context) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Common\Expressions\ParameterisedExpressionWriter.cs:line 21 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteProperty(String type, Action`1 paramsWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 49 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Forms.Exporter.FormWriter.GetWidgetProperties(Action`1 writeProperties) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Exporter\FormWriter.cs:line 145 at Mendix.Modeler.WebUI.PluginWidgets.PluginWidget.WriteWidget(IFormWriter formWriter, IWebExportContext context) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\PluginWidgets\PluginWidget.cs:line 53 at Mendix.Modeler.WebUI.Forms.Widgets.EntityWidgets.DataViews.DataView.<>c__DisplayClass65_0.<WriteTemplates>b__0() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\EntityWidgets\DataViews\DataView.cs:line 207 at Mendix.Modeler.WebUI.Forms.Exporter.FormWriter.WriteTemplate(IExportContext context, IDocumentObject documentObject, String templateName, Action writeTemplate) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Exporter\FormWriter.cs:line 134 at Mendix.Modeler.WebUI.Forms.Widgets.EntityWidgets.DataViews.DataView.WriteTemplates(FormWriter formWriter, IWebExportContext context) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\EntityWidgets\DataViews\DataView.cs:line 212 at Mendix.Modeler.WebUI.Forms.Exporter.FormWriter.WriteTemplates() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Exporter\FormWriter.cs:line 84 at Mendix.Modeler.WebUI.Forms.Exporter.FormWriter.Write() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Exporter\FormWriter.cs:line 178 at Mendix.Modeler.WebUI.Forms.Exporter.FormExporter.<>c__DisplayClass7_0.<ExportForms>b__6(<>f__AnonymousType10`3 x) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Exporter\FormExporter.cs:line 85 at System.Linq.Parallel.ForAllOperator`1.ForAllEnumerator`1.MoveNext(TInput& currentElement, Int32& currentKey) at System.Linq.Parallel.ForAllSpoolingTask`2.SpoolingWork() at System.Linq.Parallel.SpoolingTaskBase.Work() at System.Linq.Parallel.QueryTask.BaseWork(Object unused) at System.Threading.Tasks.Task.Execute()<--- ---> (Inner Exception #1) System.ArgumentNullException: Value cannot be null. Parameter name: str at Mendix.Modeler.WebUI.Util.ObjectExtensions.NotNull[T](T str) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Util\ObjectExtensions.cs:line 10 at Mendix.Modeler.WebUI.Forms.Common.Expressions.ExpressionWriter.WriteVariable(JsonWriter writer, VariableExpr expression) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Common\Expressions\ExpressionWriter.cs:line 73 at System.Collections.Generic.List`1.ForEach(Action`1 action) at Mendix.Modeler.WebUI.Forms.Common.Expressions.ExpressionWriter.WriteFunction(JsonWriter writer, FunctionCallExpr expression) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Common\Expressions\ExpressionWriter.cs:line 63 at Mendix.Modeler.WebUI.Forms.Common.Expressions.ExpressionWriter.WriteConditional(JsonWriter writer, Expr condition, Action`1 thenAction, Action`1 elseAction) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Common\Expressions\ExpressionWriter.cs:line 98 at Mendix.Modeler.WebUI.Forms.Common.Expressions.ParameterisedExpressionWriter.Write(MicroflowExpression expression, JsonWriter writer, IExportContext context) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Common\Expressions\ParameterisedExpressionWriter.cs:line 21 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteProperty(String type, Action`1 paramsWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 49 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Export.PluginWidgets.PluginWidgetExporter.<>c__DisplayClass1_1.<WriteWidgetJson>b__1(PluginWidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\PluginWidgetExporter.cs:line 27 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteObject(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 34 at Mendix.Modeler.Utility.EnumerableUtil.ForEach[T](IEnumerable`1 source, Action`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Utility\EnumerableUtil.cs:line 148 at Mendix.Modeler.WebUI.Export.PluginWidgets.JsAsJsonWriter.WriteArray(Action`1 contentWriter) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI.Export\PluginWidgets\JsAsJsonWriter.cs:line 41 at Mendix.Modeler.WebUI.Forms.Exporter.FormWriter.GetWidgetProperties(Action`1 writeProperties) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Exporter\FormWriter.cs:line 145 at Mendix.Modeler.WebUI.PluginWidgets.PluginWidget.WriteWidget(IFormWriter formWriter, IWebExportContext context) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\PluginWidgets\PluginWidget.cs:line 53 at Mendix.Modeler.WebUI.Forms.Widgets.EntityWidgets.DataViews.DataView.<>c__DisplayClass65_0.<WriteTemplates>b__0() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\EntityWidgets\DataViews\DataView.cs:line 207 at Mendix.Modeler.WebUI.Forms.Exporter.FormWriter.WriteTemplate(IExportContext context, IDocumentObject documentObject, String templateName, Action writeTemplate) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Exporter\FormWriter.cs:line 134 at Mendix.Modeler.WebUI.Forms.Widgets.EntityWidgets.DataViews.DataView.WriteTemplates(FormWriter formWriter, IWebExportContext context) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\EntityWidgets\DataViews\DataView.cs:line 212 at Mendix.Modeler.WebUI.Forms.Exporter.FormWriter.WriteTemplates() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Exporter\FormWriter.cs:line 84 at Mendix.Modeler.WebUI.Forms.Exporter.FormWriter.Write() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Exporter\FormWriter.cs:line 178 at Mendix.Modeler.WebUI.Forms.Exporter.FormExporter.<>c__DisplayClass7_0.<ExportForms>b__6(<>f__AnonymousType10`3 x) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Exporter\FormExporter.cs:line 85 at System.Linq.Parallel.ForAllOperator`1.ForAllEnumerator`1.MoveNext(TInput& currentElement, Int32& currentKey) at System.Linq.Parallel.ForAllSpoolingTask`2.SpoolingWork() at System.Linq.Parallel.SpoolingTaskBase.Work() at System.Linq.Parallel.QueryTask.BaseWork(Object unused) at System.Threading.Tasks.Task.Execute()<---