I am getting this error when trying to create a pluggable widget with Mendix, after upgrading from webpack v4 to webpack v5: Package '***.mpk': File 'package.xml' not found. Whereas the package.xml is quite clearly in the .mpk file. I am thinking that the real error is something else – perhaps about Javascript syntax changes in the bundle produce by webpack v5. Is Mendix trying to load the Javascript (When synchronizing the project directory) or something? Here are the error details: System.AggregateException: One or more errors occurred. ---> System.NullReferenceException: Object reference not set to an instance of an object. at Mendix.Modeler.WebUI.Forms.Widgets.CustomWidgets.CustomWidget.Mendix.Modeler.WebUI.PluginWidgets.Export.IExportAsPluginWidget.get_ExportCondition() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\CustomWidgets\CustomWidget.cs:line 187 at Mendix.Modeler.WebUI.PluginWidgets.Export.PluginWidgetExtensions.<>c__DisplayClass2_0.<GetUnsupportedWidgetsInContent>b__0(Widget childOrSelf) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\PluginWidgets\Export\PluginWidgetExtensions.cs:line 45 at Mendix.Modeler.Storage.Operations.TypeWalk.ForEachObjectDo(IStorageObject root, Func`2 work, Boolean skipExcludedObjects) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Storage\Operations\TypeWalk.cs:line 88 at Mendix.Modeler.Storage.Operations.TypeWalk.ForEachObjectDo(IStorageObject root, Func`2 work, Boolean skipExcludedObjects) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Storage\Operations\TypeWalk.cs:line 93 at Mendix.Modeler.WebUI.PluginWidgets.Export.PluginWidgetExtensions.GetUnsupportedWidgetsInContent(IDocumentObject widget) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\PluginWidgets\Export\PluginWidgetExtensions.cs:line 41 at Mendix.Modeler.WebUI.PluginWidgets.Export.PluginWidgetExtensions.<>c__DisplayClass2_0.<GetUnsupportedWidgetsInContent>b__0(Widget childOrSelf) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\PluginWidgets\Export\PluginWidgetExtensions.cs:line 48 at Mendix.Modeler.Storage.Operations.TypeWalk.ForEachObjectDo(IStorageObject root, Func`2 work, Boolean skipExcludedObjects) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Storage\Operations\TypeWalk.cs:line 88 at Mendix.Modeler.Storage.Operations.TypeWalk.ForEachObjectDo(IStorageObject root, Func`2 work, Boolean skipExcludedObjects) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Storage\Operations\TypeWalk.cs:line 93 at Mendix.Modeler.WebUI.PluginWidgets.Export.PluginWidgetExtensions.GetUnsupportedWidgetsInContent(IDocumentObject widget) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\PluginWidgets\Export\PluginWidgetExtensions.cs:line 41 at Mendix.Modeler.WebUI.PluginWidgets.Export.PluginWidgetExtensions.<>c__DisplayClass2_0.<GetUnsupportedWidgetsInContent>b__0(Widget childOrSelf) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\PluginWidgets\Export\PluginWidgetExtensions.cs:line 48 at Mendix.Modeler.Storage.Operations.TypeWalk.ForEachObjectDo(IStorageObject root, Func`2 work, Boolean skipExcludedObjects) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Storage\Operations\TypeWalk.cs:line 88 at Mendix.Modeler.Storage.Operations.TypeWalk.ForEachObjectDo(IStorageObject root, Func`2 work, Boolean skipExcludedObjects) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Storage\Operations\TypeWalk.cs:line 93 at Mendix.Modeler.WebUI.PluginWidgets.Export.PluginWidgetExtensions.GetUnsupportedWidgetsInContent(IDocumentObject widget) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\PluginWidgets\Export\PluginWidgetExtensions.cs:line 41 at Mendix.Modeler.WebUI.Forms.Widgets.CustomWidgets.WidgetValue.Check(IProblems problems) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\CustomWidgets\WidgetValue.cs:line 323 at Mendix.Modeler.WebUI.Forms.Widgets.CustomWidgets.WidgetObject.<>c__DisplayClass14_0.<Check>b__0(WidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\CustomWidgets\WidgetObject.cs:line 33 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 150 at Mendix.Modeler.WebUI.Forms.Widgets.CustomWidgets.CustomWidget.Check(IProblems problems) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\CustomWidgets\CustomWidget.cs:line 236 at Mendix.Modeler.WebUI.Forms.Widgets.LayoutWidgets.DivContainers.DivContainer.Check(IProblems problems) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\LayoutWidgets\DivContainers\DivContainer.cs:line 28 at Mendix.Modeler.WebUI.Forms.Widgets.LayoutWidgets.DivContainers.DivContainer.Check(IProblems problems) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\LayoutWidgets\DivContainers\DivContainer.cs:line 28 at Mendix.Modeler.WebUI.Forms.Widgets.LayoutWidgets.DivContainers.DivContainer.Check(IProblems problems) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\LayoutWidgets\DivContainers\DivContainer.cs:line 28 at Mendix.Modeler.WebUI.Forms.Documents.Snippets.Snippet.Check(IProblems problems) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Documents\Snippets\Snippet.cs:line 47 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 150 at Mendix.Modeler.Common.ResolveCache.TrackResolves(Action code) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Common\Problems\ResolveCache.cs:line 68 at Mendix.Modeler.Projects.Checks.DocumentCheck.CheckDocument(IDocument document, IUsages usages) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Projects\Checks\DocumentCheck.cs:line 45 at Mendix.Modeler.Projects.Checks.DocumentCheck.Check(IProject project, ProjectChanges changes, IProblems problems) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Projects\Checks\DocumentCheck.cs:line 30 at Mendix.Modeler.Projects.Checks.ProjectChecker.<>c__DisplayClass5_0.<Check>b__0(ProjectChanges changes) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Projects\Checks\ProjectChecker.cs:line 54 at Mendix.Modeler.Projects.Checks.ChangedDocumentTracker.TryProcessChangesSync(Action`1 changeProcessor) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Projects\Checks\ChangedDocumentTracker.cs:line 35 at Mendix.Modeler.Projects.Checks.ProjectChecker.Check(IProject project) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Projects\Checks\ProjectChecker.cs:line 37 at Mendix.Modeler.Common.BackgroundCheckRunner.Check(IProject project) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Common\Problems\BackgroundCheckRunner.cs:line 103 at Mendix.Modeler.Common.BackgroundCheckRunner.<>c__DisplayClass5_0.<StartChecking>b__0() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Common\Problems\BackgroundCheckRunner.cs:line 46 --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Mendix.Modeler.Common.BackgroundCheckRunner.<Start>d__4.MoveNext() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Common\Problems\BackgroundCheckRunner.cs:line 30 --- End of inner exception stack trace --- ---> (Inner Exception #0) System.NullReferenceException: Object reference not set to an instance of an object. at Mendix.Modeler.WebUI.Forms.Widgets.CustomWidgets.CustomWidget.Mendix.Modeler.WebUI.PluginWidgets.Export.IExportAsPluginWidget.get_ExportCondition() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\CustomWidgets\CustomWidget.cs:line 187 at Mendix.Modeler.WebUI.PluginWidgets.Export.PluginWidgetExtensions.<>c__DisplayClass2_0.<GetUnsupportedWidgetsInContent>b__0(Widget childOrSelf) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\PluginWidgets\Export\PluginWidgetExtensions.cs:line 45 at Mendix.Modeler.Storage.Operations.TypeWalk.ForEachObjectDo(IStorageObject root, Func`2 work, Boolean skipExcludedObjects) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Storage\Operations\TypeWalk.cs:line 88 at Mendix.Modeler.Storage.Operations.TypeWalk.ForEachObjectDo(IStorageObject root, Func`2 work, Boolean skipExcludedObjects) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Storage\Operations\TypeWalk.cs:line 93 at Mendix.Modeler.WebUI.PluginWidgets.Export.PluginWidgetExtensions.GetUnsupportedWidgetsInContent(IDocumentObject widget) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\PluginWidgets\Export\PluginWidgetExtensions.cs:line 41 at Mendix.Modeler.WebUI.PluginWidgets.Export.PluginWidgetExtensions.<>c__DisplayClass2_0.<GetUnsupportedWidgetsInContent>b__0(Widget childOrSelf) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\PluginWidgets\Export\PluginWidgetExtensions.cs:line 48 at Mendix.Modeler.Storage.Operations.TypeWalk.ForEachObjectDo(IStorageObject root, Func`2 work, Boolean skipExcludedObjects) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Storage\Operations\TypeWalk.cs:line 88 at Mendix.Modeler.Storage.Operations.TypeWalk.ForEachObjectDo(IStorageObject root, Func`2 work, Boolean skipExcludedObjects) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Storage\Operations\TypeWalk.cs:line 93 at Mendix.Modeler.WebUI.PluginWidgets.Export.PluginWidgetExtensions.GetUnsupportedWidgetsInContent(IDocumentObject widget) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\PluginWidgets\Export\PluginWidgetExtensions.cs:line 41 at Mendix.Modeler.WebUI.PluginWidgets.Export.PluginWidgetExtensions.<>c__DisplayClass2_0.<GetUnsupportedWidgetsInContent>b__0(Widget childOrSelf) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\PluginWidgets\Export\PluginWidgetExtensions.cs:line 48 at Mendix.Modeler.Storage.Operations.TypeWalk.ForEachObjectDo(IStorageObject root, Func`2 work, Boolean skipExcludedObjects) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Storage\Operations\TypeWalk.cs:line 88 at Mendix.Modeler.Storage.Operations.TypeWalk.ForEachObjectDo(IStorageObject root, Func`2 work, Boolean skipExcludedObjects) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Storage\Operations\TypeWalk.cs:line 93 at Mendix.Modeler.WebUI.PluginWidgets.Export.PluginWidgetExtensions.GetUnsupportedWidgetsInContent(IDocumentObject widget) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\PluginWidgets\Export\PluginWidgetExtensions.cs:line 41 at Mendix.Modeler.WebUI.Forms.Widgets.CustomWidgets.WidgetValue.Check(IProblems problems) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\CustomWidgets\WidgetValue.cs:line 323 at Mendix.Modeler.WebUI.Forms.Widgets.CustomWidgets.WidgetObject.<>c__DisplayClass14_0.<Check>b__0(WidgetProperty property) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\CustomWidgets\WidgetObject.cs:line 33 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 150 at Mendix.Modeler.WebUI.Forms.Widgets.CustomWidgets.CustomWidget.Check(IProblems problems) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\CustomWidgets\CustomWidget.cs:line 236 at Mendix.Modeler.WebUI.Forms.Widgets.LayoutWidgets.DivContainers.DivContainer.Check(IProblems problems) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\LayoutWidgets\DivContainers\DivContainer.cs:line 28 at Mendix.Modeler.WebUI.Forms.Widgets.LayoutWidgets.DivContainers.DivContainer.Check(IProblems problems) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\LayoutWidgets\DivContainers\DivContainer.cs:line 28 at Mendix.Modeler.WebUI.Forms.Widgets.LayoutWidgets.DivContainers.DivContainer.Check(IProblems problems) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Widgets\LayoutWidgets\DivContainers\DivContainer.cs:line 28 at Mendix.Modeler.WebUI.Forms.Documents.Snippets.Snippet.Check(IProblems problems) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.WebUI\Forms\Documents\Snippets\Snippet.cs:line 47 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 150 at Mendix.Modeler.Common.ResolveCache.TrackResolves(Action code) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Common\Problems\ResolveCache.cs:line 68 at Mendix.Modeler.Projects.Checks.DocumentCheck.CheckDocument(IDocument document, IUsages usages) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Projects\Checks\DocumentCheck.cs:line 45 at Mendix.Modeler.Projects.Checks.DocumentCheck.Check(IProject project, ProjectChanges changes, IProblems problems) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Projects\Checks\DocumentCheck.cs:line 30 at Mendix.Modeler.Projects.Checks.ProjectChecker.<>c__DisplayClass5_0.<Check>b__0(ProjectChanges changes) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Projects\Checks\ProjectChecker.cs:line 54 at Mendix.Modeler.Projects.Checks.ChangedDocumentTracker.TryProcessChangesSync(Action`1 changeProcessor) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Projects\Checks\ChangedDocumentTracker.cs:line 35 at Mendix.Modeler.Projects.Checks.ProjectChecker.Check(IProject project) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Projects\Checks\ProjectChecker.cs:line 37 at Mendix.Modeler.Common.BackgroundCheckRunner.Check(IProject project) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Common\Problems\BackgroundCheckRunner.cs:line 103 at Mendix.Modeler.Common.BackgroundCheckRunner.<>c__DisplayClass5_0.<StartChecking>b__0() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Common\Problems\BackgroundCheckRunner.cs:line 46 --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Mendix.Modeler.Common.BackgroundCheckRunner.<Start>d__4.MoveNext() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Common\Problems\BackgroundCheckRunner.cs:line 30<---