An unhandled error occured.

[kaliboi]

The bug
Whenever I delete unwanted clipboard contents from Shapeshifter, it throws an error message as mentioned in issue #593.

Error Message in Log File:
2019-02-19 22:24:58.578 [#10724] [] [ERR]
An unhandled error occured.
System.InvalidOperationException: An ItemsControl is inconsistent with its items source.
See the inner exception for more information. ---> System.Exception: Information for developers (use Text Visualizer to read this):
This exception was thrown because the generator for control 'System.Windows.Controls.ListBox Items.Count:5' with name '(unnamed)' has received sequence of CollectionChanged events that do not agree with the current state of the Items collection. The following differences were detected:
Accumulated count 3 is different from actual count 5. [Accumulated count is (Count at last Reset + #Adds - #Removes since last Reset).]

One or more of the following sources may have raised the wrong events:
System.Windows.Controls.ItemContainerGenerator
System.Windows.Controls.ItemCollection
System.Windows.Data.ListCollectionView
System.Collections.Generic.List`1[[Shapeshifter.WindowsDesktop.Data.Actions.Interfaces.IAction, Shapeshifter, Version=6.2018.922.2862, Culture=neutral, PublicKeyToken=null]]
(The starred sources are considered more likely to be the cause of the problem.)

The most common causes are (a) changing the collection or its Count without raising a corresponding event, and (b) raising an event with an incorrect index or item parameter.

The exception's stack trace describes how the inconsistencies were detected, not how they occurred. To get a more timely exception, set the attached property 'PresentationTraceSources.TraceLevel' on the generator to value 'High' and rerun the scenario. One way to do this is to run a command similar to the following:
System.Diagnostics.PresentationTraceSources.SetTraceLevel(myItemsControl.ItemContainerGenerator, System.Diagnostics.PresentationTraceLevel.High)
from the Immediate window. This causes the detection logic to run after every CollectionChanged event, so it will slow down the application.

--- End of inner exception stack trace ---
at System.Windows.Controls.ItemContainerGenerator.Verify()
at System.Windows.Controls.VirtualizingStackPanel.MeasureChild(IItemContainerGenerator& generator, IContainItemStorage& itemStorageProvider, IContainItemStorage& parentItemStorageProvider, Object& parentItem, Boolean& hasUniformOrAverageContainerSizeBeenSet, Double& computedUniformOrAverageContainerSize, Double& computedUniformOrAverageContainerPixelSize, Boolean& computedAreContainersUniformlySized, Boolean& hasAnyContainerSpanChanged, IList& items, Object& item, IList& children, Int32& childIndex, Boolean& visualOrderChanged, Boolean& isHorizontal, Size& childConstraint, Rect& viewport, VirtualizationCacheLength& cacheSize, VirtualizationCacheLengthUnit& cacheUnit, Boolean& foundFirstItemInViewport, Double& firstItemInViewportOffset, Size& stackPixelSize, Size& stackPixelSizeInViewport, Size& stackPixelSizeInCacheBeforeViewport, Size& stackPixelSizeInCacheAfterViewport, Size& stackLogicalSize, Size& stackLogicalSizeInViewport, Size& stackLogicalSizeInCacheBeforeViewport, Size& stackLogicalSizeInCacheAfterViewport, Boolean& mustDisableVirtualization, Boolean isBeforeFirstItem, Boolean isAfterFirstItem, Boolean isAfterLastItem, Boolean skipActualMeasure, Boolean skipGeneration, Boolean& hasBringIntoViewContainerBeenMeasured, Boolean& hasVirtualizingChildren)
at System.Windows.Controls.VirtualizingStackPanel.MeasureOverrideImpl(Size constraint, Nullable1& lastPageSafeOffset, List1& previouslyMeasuredOffsets, Nullable`1& lastPagePixelSize, Boolean remeasure)
at System.Windows.Controls.VirtualizingStackPanel.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.ContextLayoutManager.UpdateLayout()
at System.Windows.Controls.VirtualizingStackPanel.<>c__DisplayClass94_0.b__0()
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)

2019-02-19 22:24:58.809 [#10724] [] [VRB]
Reporting the log entry An unhandled error occured..

Desktop:
Windows 10 Pro 1803
IE 11, Chrome 72.0.3626

[ffMathy]

Shapeshifter is currently quite dormant unfortunately. I'm the sole maintainer, doing this for fun, and I have many other open source projects of my making to attend to.

If you'd like to show your support and potentially accelerate the fix of this issue, consider becoming a sponsor on Patreon. That way, you don't actually pay anything unless major updates arrive. And I don't expect them to arrive until quite some time, but if enough people become sponsors, I'll probably start doing this as my main project.

I hope you understand!