As suggested in the orginal support ticket 1430154 I'm opening a separate bug reprot for the RadRichTextBox.

Visual Studio 2019 solution to reproduce the problem is attached to the bug report.

The exception is thrown in RadDocument.IsInNonEditableRange() method, which is called before measuring the document. When using a format provider, the error is thrown but the document can still be opened in RichTextBox. In binding scenario, the document is not imported.

Workaround: Ensure the document is measured before assigning it to RadRichTextBox.

The caret position does not move at the end of the line with continuous text (see attached).

To reproduce:

• Create two lists one after another
• Select the second by using the keyboard 
• Press delete and then Ctrl+z (undo)

This works fine when the list is selected with the mouse. 

To reproduce:

- Add a multilevel list to a document and export it to HTML

- Import the document again the list is changed and the values are not correct.

When a hyperlink uri contains a symbol that needs to be escaped (e.g. ')'), the exported document is corrupted.

Use Destination styles does not appear in the paste options popup control. It only appears in the RadRibbonDropDownButton.

Invoking the same Paste Options command for a second time does not close the popup. It is closed when another Paste Options command is executed.

Support should be implemented for importing height CSS property applied to HTML table cells.

Importing padding CSS style property with shorthand value produces an incorrect result. 
Example: 
Importing padding: 5px; style is imported as padding-top: 5px, padding-right: 0px, padding-bottom: 0px, padding-left: 0px

Padding syntax can be seen in the specification.

Workaround: Apply padding values for all four sides.

 Incorrect behavior when setting the table cells padding

Steps to reproduce:

- Insert a table

- Open Table Properties

- Clear the value in the "Left" field 

- Check "Same for all sides"

- Click OK

When the popup is located on the bottom side of the document and it is also close to the end of the presenter and a user opens it, then the popup goes outside the area.

When trying to import a document containing bookmark and BookmarkRangeEnd is after the last paragraph, a StackOverflowException is thrown in IntervalNode while trying to rebuild the document cache. (RadDocumentChildrenCache.RebuildTree()).

The same could be observed if the bookmark end is last in the header/footer, between table cells in the RadDocument body, or when all paragraphs after the bookmark range end are hidden (with vanish property).

Workaround: Detect the problematic annotations and remove them:
foreach (var rangeStart in document.EnumerateChildrenOfType<AnnotationRangeStart>())
{
    if (rangeStart.End == null || rangeStart.End.Parent == null || rangeStart.End.Parent.Parent == null)
    {
        //MessageBox.Show("This indicates a problem.");
        rangeStart.Parent.Children.Remove(rangeStart);
    }
}

Note: Until 2017 R2 SP1 release StackOverflowException is thrown, after this release an ArgumentException should be thrown.

There is a NullReferenceException thrown while trying to compare positions for restoring them after pasting the document. The exception is handled but after it is thrown, the layout stops updating.

To reproduce: 

protected override void OnClosing(CancelEventArgs e)
{
    this.radRichTextBox.Document = null;
    base.OnClosing(e);
}

Use the attached project to reproduce. 

- Click the "Go To endPosition" button. The Caret remains on the same line.

The font family of the fields is changed to Times New Roman while importing RTF documents. The issue is a regression caused in 2019 R3 (LIB 2019.2.610)

StackOverflowException is sometimes thrown while a document containing annotations is updated in the main thread (e.g. by typing in it), and spell checking is enabled.

The exception is thrown in a background thread, which call stack similar to this one:

2f89dfe8 00566287 Telerik.Windows.Documents.Cache.IntervalTree.IntervalNode`2[[System.__Canon, mscorlib],[Telerik.Windows.Documents.Cache.IntervalTree.HierarchicalIndexStruct, Telerik.Windows.Documents]]..ctor(System.Collections.Generic.IEnumerable`1<System.__Canon>)
2f89e084 00566287 Telerik.Windows.Documents.Cache.IntervalTree.IntervalNode`2[[System.__Canon, mscorlib],
...
2f89e4dc 00565cd8 Telerik.Windows.Documents.Cache.RadDocumentChildrenCache.RebuildTree()
2f89e52c 005658c1 Telerik.Windows.Documents.Cache.RadDocumentChildrenCache.Rebuild()
2f89e538 1413b704 Telerik.Windows.Documents.Cache.RadChildrenCacheBase`1[[System.__Canon, mscorlib]].EnsureValid()
2f89e568 00568c72 Telerik.Windows.Documents.Cache.RadDocumentChildrenCache.ContainsAnnotationMarkersOfType[[System.__Canon, mscorlib]]()
2f89e5c0 00568b29 Telerik.Windows.Documents.Cache.RadDocumentChildrenCache.GetContainingAnnotationRanges[[System.__Canon, mscorlib]](Telerik.Windows.Documents.Model.Inline, Boolean)
2f89e618 0056896f Telerik.Windows.Documents.Model.RadDocument.GetContainingAnnotationRanges[[System.__Canon, mscorlib]](Telerik.Windows.Documents.Model.Inline, System.Predicate`1<System.__Canon>, Boolean)
2f89e654 1b6b76d3 Telerik.Windows.Documents.Proofing.DocumentProofingManager.IsPositionInIgnoredRange(Telerik.Windows.Documents.DocumentPosition)
2f89e664 1b6b72e7 Telerik.Windows.Documents.Proofing.DocumentProofingManager+<SplitRangeToUpdate>d__2.MoveNext()
2f89e690 1b6b7019 Telerik.Windows.Documents.Proofing.DocumentProofingManager.UpdateIncorrectWordsList(Telerik.Windows.Documents.DocumentPosition, Telerik.Windows.Documents.DocumentPosition)
2f89e6c0 1b6b6ef2 Telerik.Windows.Documents.UI.Layers.TextDecorationLayers.ProofingErrorsDecorationUILayer+<>c__DisplayClass9.<MarkBoxesWithSpellingErrorsAsynch>b__5()
2f89e6d0 1b612094 Telerik.Windows.Documents.Utils.DelayedExecution.ExecuteAction(Boolean)
2f89e6e4 1b6b6e34 Telerik.Windows.Documents.Utils.DelayedExecution.OnThreadingTimer(System.Object)
2f89e704 65fa5b38 System.Threading.TimerQueueTimer.CallCallbackInContext(System.Object)
2f89e708 65fc4157 System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
2f89e774 65fc4096 System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
2f89e788 65fa5a81 System.Threading.TimerQueueTimer.CallCallback()
2f89e7bc 65fa593c System.Threading.TimerQueueTimer.Fire()
2f89e7fc 65fa5861 System.Threading.TimerQueue.FireNextTimers()
2f89e83c 65fa5724 System.Threading.TimerQueue.AppDomainTimerCallback()
2f89ea68 66d73de2 [DebuggerU2MCatchHandlerFrame: 2f89ea68] 

Note: Until 2017 R2 SP1 release StackOverflowException is thrown, after this release an ArgumentException should be thrown.
Declined: Not reproducible anymore.

Quickly adding/removing of tab stop from the document's ruler crashes the application.

1. Open RadRichTextBox
2. Click to Home tab -> Paragraph group-> Multilevel list button
4. Click to "Define New List Style"
5. In "Apply formatting to" select 4th level. Don't select '1','2','3' beforehand, select '4' right after '1'st level.

Observed result: All text except the 4th level is bold.

Expected result: Only 4th level text is bold.