In my modeler the IDE is giving an error that is not very specific…. System.InvalidOperationException: Cannot perform this operation while dispatcher processing is suspended. at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame) at System.Windows.Threading.DispatcherOperation.Wait(TimeSpan timeout) at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherOperation operation, CancellationToken cancellationToken, TimeSpan timeout) at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs) at System.Windows.Threading.Dispatcher.Invoke(Delegate method, DispatcherPriority priority, Object[] args) at Eto.Wpf.WpfExtensions.<>c__DisplayClass10_0.<EnsureLoaded>b__0() at Eto.Wpf.Forms.Controls.ScrollableHandler.get_ClientSize() at Mendix.Modeler.Core.View.TabbedEditors.Canvas.UpdateViewPort(Nullable`1 newScrollPosition) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core.View.CrossPlatform\TabbedEditors\Canvas.cs:line 274 at Mendix.Modeler.Core.View.DomainModels.DomainModelEditor.UpdateCanvasDimensions() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core.View.CrossPlatform\DomainModels\DomainModelEditor.cs:line 234 at Mendix.Modeler.Core.View.DomainModels.DomainModelEditor.OnShown() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core.View.CrossPlatform\DomainModels\DomainModelEditor.cs:line 245 at Mendix.Modeler.Core.View.TabbedEditors.TabbedCanvasEditor.<>c__DisplayClass12_0.<.ctor>b__3(Object _, EventArgs _) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core.View.CrossPlatform\TabbedEditors\TabbedCanvasEditor.cs:line 54 at Eto.Forms.Control.OnShown(EventArgs e) at Eto.Forms.Control.Callback.OnShown(Control widget, EventArgs e) at Eto.Wpf.Forms.WpfFrameworkElement`3.HandleIsVisibleChanged(Object sender, DependencyPropertyChangedEventArgs e) at System.Windows.UIElement.OnIsVisibleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args) at System.Windows.UIElement.UpdateIsVisibleCache() at System.Windows.UIElement.InvalidateForceInheritPropertyOnChildren(Visual v, DependencyProperty property) at System.Windows.UIElement.OnIsVisibleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args) at System.Windows.UIElement.UpdateIsVisibleCache() at System.Windows.UIElement.InvalidateForceInheritPropertyOnChildren(Visual v, DependencyProperty property) at System.Windows.UIElement.OnIsVisibleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args) at System.Windows.UIElement.UpdateIsVisibleCache() at System.Windows.UIElement.InvalidateForceInheritPropertyOnChildren(Visual v, DependencyProperty property) at System.Windows.UIElement.OnIsVisibleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args) at System.Windows.UIElement.UpdateIsVisibleCache() at System.Windows.UIElement.InvalidateForceInheritPropertyOnChildren(Visual v, DependencyProperty property) at System.Windows.UIElement.OnIsVisibleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args) at System.Windows.UIElement.UpdateIsVisibleCache() at System.Windows.UIElement.InvalidateForceInheritPropertyOnChildren(Visual v, DependencyProperty property) at System.Windows.UIElement.OnIsVisibleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args) at System.Windows.UIElement.UpdateIsVisibleCache() at System.Windows.UIElement.InvalidateForceInheritPropertyOnChildren(Visual v, DependencyProperty property) at System.Windows.UIElement.OnIsVisibleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args) at System.Windows.UIElement.UpdateIsVisibleCache() at System.Windows.UIElement.InvalidateForceInheritPropertyOnChildren(Visual v, DependencyProperty property) at System.Windows.UIElement.OnIsVisibleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args) at System.Windows.UIElement.UpdateIsVisibleCache() at System.Windows.UIElement.InvalidateForceInheritPropertyOnChildren(Visual v, DependencyProperty property) at System.Windows.UIElement.OnIsVisibleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args) at System.Windows.UIElement.UpdateIsVisibleCache() at System.Windows.UIElement.InvalidateForceInheritPropertyOnChildren(Visual v, DependencyProperty property) at System.Windows.UIElement.OnIsVisibleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args) at System.Windows.UIElement.UpdateIsVisibleCache() at System.Windows.UIElement.InvalidateForceInheritPropertyOnChildren(Visual v, DependencyProperty property) at System.Windows.UIElement.OnIsVisibleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args) at System.Windows.UIElement.UpdateIsVisibleCache() at System.Windows.UIElement.InvalidateForceInheritPropertyOnChildren(Visual v, DependencyProperty property) at System.Windows.UIElement.OnIsVisibleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args) at System.Windows.UIElement.UpdateIsVisibleCache() at System.Windows.UIElement.OnVisualParentChanged(DependencyObject oldParent) at System.Windows.Media.Visual.FireOnVisualParentChanged(DependencyObject oldParent) at System.Windows.Media.Visual.AddVisualChild(Visual child) at System.Windows.Controls.ContentPresenter.UseContentTemplate.BuildVisualTree(FrameworkElement container) at System.Windows.StyleHelper.ApplyTemplateContent(UncommonField`1 dataField, DependencyObject container, FrameworkElementFactory templateRoot, Int32 lastChildIndex, HybridDictionary childIndexFromChildID, FrameworkTemplate frameworkTemplate) at System.Windows.FrameworkTemplate.ApplyTemplateContent(UncommonField`1 templateDataField, FrameworkElement container) at System.Windows.FrameworkElement.ApplyTemplate() at System.Windows.FrameworkElement.MeasureCore(Size availableSize) at System.Windows.UIElement.Measure(Size availableSize) at System.Windows.ContextLayoutManager.UpdateLayout() at System.Windows.Controls.TabItem.OnPreviewGotKeyboardFocus(KeyboardFocusChangedEventArgs e) at ActiproSoftware.Windows.Controls.Docking.AdvancedTabItem.OnPreviewGotKeyboardFocus(KeyboardFocusChangedEventArgs e) at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target) at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised) at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args) at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args) at System.Windows.Input.InputManager.ProcessStagingArea() at System.Windows.Input.KeyboardDevice.TryChangeFocus(DependencyObject newFocus, IKeyboardInputProvider keyboardInputProvider, Boolean askOld, Boolean askNew, Boolean forceToNullIfFailed) at System.Windows.Input.KeyboardDevice.Focus(DependencyObject focus, Boolean askOld, Boolean askNew, Boolean forceToNullIfFailed) at System.Windows.Input.KeyboardDevice.Focus(IInputElement element) at System.Windows.UIElement.Focus() at System.Windows.Controls.TabItem.SetFocus() at System.Windows.Controls.TabControl.OnSelectionChanged(SelectionChangedEventArgs e) at ActiproSoftware.Windows.Controls.Docking.AdvancedTabControl.OnSelectionChanged(SelectionChangedEventArgs e) at ActiproSoftware.Windows.Controls.Docking.Primitives.TabbedMdiContainerTabControl.OnSelectionChanged(SelectionChangedEventArgs e) at System.Windows.Controls.Primitives.Selector.SetSelectedHelper(Object item, FrameworkElement UI, Boolean selected) at System.Windows.Controls.Primitives.Selector.OnSelected(Object sender, RoutedEventArgs e) at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised) at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args) at ActiproSoftware.Windows.Controls.Docking.AdvancedTabItem.OnSelected(RoutedEventArgs e) at System.Windows.Controls.TabItem.OnIsSelectedChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args) at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType) at System.Windows.DependencyObject.SetValueCommon(DependencyProperty dp, Object value, PropertyMetadata metadata, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType, Boolean isInternal) at ActiproSoftware.Windows.Controls.Docking.AdvancedTabItem.y4i(Object , InputPointerButtonEventArgs ) at ActiproSoftware.Windows.Input.InputAdapter.WEA(Object , InputEventArgs , InputPointerButtonKind ) at ActiproSoftware.Windows.Input.InputAdapter.HEY(Object , InputEventArgs ) at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target) at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised) at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args) at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args) at System.Windows.Input.InputManager.ProcessStagingArea() at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport) at System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel) at System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)