Crash when right click "delete" assembly that no longer exists on disk - 7.2 RC2

[grahambunce]

Open ILSpy that has a previously opened assembly in the Assembly list but no longer exists (Yellow warning icon, tooltip "assembly could not be loaded, click here for details")
Right click on assembly to see context menu
Click "remove"
System crash as below

Workaround: Select the item instead and press "DEL" then item is correctly removed from the list

System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
   at ICSharpCode.TreeView.TreeFlattener.get_Item(Int32 index) in /home/runner/work/AvaloniaILSpy/AvaloniaILSpy/SharpTreeView/TreeFlattener.cs:line 64
   at Avalonia.Controls.ItemsSourceView`1.GetAt(Int32 index) in /_/src/Avalonia.Controls/ItemsSourceView.cs:line 243
   at Avalonia.Controls.Selection.SelectedItems`1.GetEnumerator()+MoveNext() in /_/src/Avalonia.Controls/Selection/SelectedItems.cs:line 89
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at Avalonia.Controls.Primitives.SelectingItemsControl.OnSelectionModelSelectionChanged(Object sender, SelectionModelSelectionChangedEventArgs e) in /_/src/Avalonia.Controls/Primitives/SelectingItemsControl.cs:line 818
   at Avalonia.Controls.Selection.SelectionModel`1.CommitOperation(Operation operation, Boolean raisePropertyChanged) in /_/src/Avalonia.Controls/Selection/SelectionModel.cs:line 706
   at Avalonia.Controls.Selection.SelectionModel`1.BatchUpdateOperation.Dispose() in /_/src/Avalonia.Controls/Selection/SelectionModel.cs:line 767
   at Avalonia.Controls.Selection.InternalSelectionModel.OnSelectedItemsCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e) in /_/src/Avalonia.Controls/Selection/InternalSelectionModel.cs:line 277
   at Avalonia.Collections.AvaloniaList`1.Clear() in /_/src/Avalonia.Base/Collections/AvaloniaList.cs:line 229
   at Avalonia.Collections.AvaloniaList`1.System.Collections.IList.Clear() in /_/src/Avalonia.Base/Collections/AvaloniaList.cs:line 554
   at ICSharpCode.TreeView.SharpTreeView.SetSelectedNodes(IEnumerable`1 nodes) in /home/runner/work/AvaloniaILSpy/AvaloniaILSpy/SharpTreeView/SharpTreeView.cs:line 754
   at ICSharpCode.TreeView.SharpTreeView.UpdateFocusedNode(List`1 newSelection, Int32 topSelectedIndex) in /home/runner/work/AvaloniaILSpy/AvaloniaILSpy/SharpTreeView/SharpTreeView.cs:line 184
   at ICSharpCode.TreeView.TreeFlattener.NodesRemoved(Int32 index, IEnumerable`1 nodes) in /home/runner/work/AvaloniaILSpy/AvaloniaILSpy/SharpTreeView/TreeFlattener.cs:line 51
   at ICSharpCode.TreeView.SharpTreeNode.OnChildrenChanged(NotifyCollectionChangedEventArgs e) in /home/runner/work/AvaloniaILSpy/AvaloniaILSpy/SharpTreeView/SharpTreeNode.cs:line 189
   at ICSharpCode.TreeView.SharpTreeNodeCollection.OnCollectionChanged(NotifyCollectionChangedEventArgs e) in /home/runner/work/AvaloniaILSpy/AvaloniaILSpy/SharpTreeView/SharpTreeNodeCollection.cs:line 33
   at ICSharpCode.TreeView.SharpTreeNodeCollection.RemoveRange(Int32 index, Int32 count) in /home/runner/work/AvaloniaILSpy/AvaloniaILSpy/SharpTreeView/SharpTreeNodeCollection.cs:line 124
   at ICSharpCode.ILSpy.TreeNodes.AssemblyListTreeNode.<>c__DisplayClass6_0.<BindToObservableCollection>b__1(Object sender, NotifyCollectionChangedEventArgs e) in /home/runner/work/AvaloniaILSpy/AvaloniaILSpy/ILSpy.Core/TreeNodes/AssemblyListTreeNode.cs:line 67
   at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
   at System.Collections.ObjectModel.ObservableCollection`1.RemoveItem(Int32 index)
   at System.Collections.ObjectModel.Collection`1.Remove(T item)
   at ICSharpCode.ILSpy.AssemblyList.Unload(LoadedAssembly assembly) in /home/runner/work/AvaloniaILSpy/AvaloniaILSpy/ILSpy.Core/AssemblyList.cs:line 252
   at ICSharpCode.ILSpy.TreeNodes.AssemblyTreeNode.DeleteCore() in /home/runner/work/AvaloniaILSpy/AvaloniaILSpy/ILSpy.Core/TreeNodes/AssemblyTreeNode.cs:line 258
   at ICSharpCode.ILSpy.TreeNodes.AssemblyTreeNode.Delete() in /home/runner/work/AvaloniaILSpy/AvaloniaILSpy/ILSpy.Core/TreeNodes/AssemblyTreeNode.cs:line 253
   at ICSharpCode.ILSpy.TreeNodes.RemoveAssembly.Execute(TextViewContext context) in /home/runner/work/AvaloniaILSpy/AvaloniaILSpy/ILSpy.Core/TreeNodes/AssemblyTreeNode.cs:line 380
   at ICSharpCode.ILSpy.ContextMenuProvider.<>c__DisplayClass12_1.<ShowContextMenu>b__2(Object <p0>, RoutedEventArgs <p1>) in /home/runner/work/AvaloniaILSpy/AvaloniaILSpy/ILSpy.Core/ContextMenuEntry.cs:line 236
   at Avalonia.Interactivity.EventRoute.RaiseEventImpl(RoutedEventArgs e) in /_/src/Avalonia.Interactivity/EventRoute.cs:line 152
   at Avalonia.Interactivity.EventRoute.RaiseEvent(IInteractive source, RoutedEventArgs e) in /_/src/Avalonia.Interactivity/EventRoute.cs:line 79
   at Avalonia.Interactivity.Interactive.RaiseEvent(RoutedEventArgs e) in /_/src/Avalonia.Interactivity/Interactive.cs:line 123
   at Avalonia.Controls.MenuItem.Avalonia.Controls.IMenuItem.RaiseClick() in /_/src/Avalonia.Controls/MenuItem.cs:line 333
   at Avalonia.Controls.Platform.DefaultMenuInteractionHandler.Click(IMenuItem item) in /_/src/Avalonia.Controls/Platform/DefaultMenuInteractionHandler.cs:line 456
   at Avalonia.Controls.Platform.DefaultMenuInteractionHandler.PointerReleased(Object sender, PointerReleasedEventArgs e) in /_/src/Avalonia.Controls/Platform/DefaultMenuInteractionHandler.cs:line 408
   at Avalonia.Interactivity.EventRoute.RaiseEventImpl(RoutedEventArgs e) in /_/src/Avalonia.Interactivity/EventRoute.cs:line 152
   at Avalonia.Interactivity.EventRoute.RaiseEvent(IInteractive source, RoutedEventArgs e) in /_/src/Avalonia.Interactivity/EventRoute.cs:line 79
   at Avalonia.Interactivity.Interactive.RaiseEvent(RoutedEventArgs e) in /_/src/Avalonia.Interactivity/Interactive.cs:line 123
   at Avalonia.Input.MouseDevice.MouseUp(IMouseDevice device, UInt64 timestamp, IInputRoot root, Point p, PointerPointProperties props, KeyModifiers inputModifiers) in /_/src/Avalonia.Input/MouseDevice.cs:line 311
   at Avalonia.Input.MouseDevice.ProcessRawEvent(RawPointerEventArgs e) in /_/src/Avalonia.Input/MouseDevice.cs:line 144
   at Avalonia.Input.InputManager.ProcessInput(RawInputEventArgs e) in /_/src/Avalonia.Input/InputManager.cs:line 37
   at Avalonia.RawEventGrouper.DispatchFromQueue() in /_/src/Shared/RawEventGrouping.cs:line 54
   at Avalonia.Threading.JobRunner.RunJobs(Nullable`1 priority) in /_/src/Avalonia.Base/Threading/JobRunner.cs:line 37
   at Avalonia.X11.X11PlatformThreading.HandleX11(CancellationToken cancellationToken) in /_/src/Avalonia.X11/X11PlatformThreading.cs:line 169
   at Avalonia.X11.X11PlatformThreading.RunLoop(CancellationToken cancellationToken) in /_/src/Avalonia.X11/X11PlatformThreading.cs:line 245
   at Avalonia.Threading.Dispatcher.MainLoop(CancellationToken cancellationToken) in /_/src/Avalonia.Base/Threading/Dispatcher.cs:line 65
   at Avalonia.Controls.ApplicationLifetimes.ClassicDesktopStyleApplicationLifetime.Start(String[] args) in /_/src/Avalonia.Controls/ApplicationLifetimes/ClassicDesktopStyleApplicationLifetime.cs:line 120
   at Avalonia.ClassicDesktopStyleApplicationLifetimeExtensions.StartWithClassicDesktopLifetime[T](T builder, String[] args, ShutdownMode shutdownMode) in /_/src/Avalonia.Controls/ApplicationLifetimes/ClassicDesktopStyleApplicationLifetime.cs:line 209
   at ICSharpCode.ILSpy.Program.Main(String[] args) in /home/runner/work/AvaloniaILSpy/AvaloniaILSpy/ILSpy/Program.cs:line 22