If you highlight a section of text and apply styles to it like bold/italic/underline and place your cursor at the end of that text the Clear All Formatting button does not work. If you turn on those styles and then type some text and place your cursor at the end of that text it does work. The difference in the XAML is that in the first case the styles are only on the span of text itself while in the second the styles are on the span and the paragraph. I have attached a GIF of steps to reproduce and the XAML from the editor before clicking the Clear All Formatting button.

NullReferenceException is thrown when measuring a document with floating image as the first element on a second page. The same problem can be observed during copy/paste of content, but with slightly different call stack: 

System.NullReferenceException: Object reference not set to an instance of an object.
   at Telerik.Windows.Documents.Layout.LayoutBox.get_ValidParent()
   at Telerik.Windows.Documents.DocumentPosition.GetCurrentParagraphBox()
   at Telerik.Windows.Controls.RichTextBoxUI.RadRichTextBoxRulerController.GetCurrentParagraphBox()
   at Telerik.Windows.Controls.RichTextBoxUI.RadRichTextBoxRulerController.AssociatedRichTextBox_LayoutUpdated(Object sender, EventArgs e)

Depending on the document structure, an InvalidOperationException with message "Removed LayoutBox should not be split. Such operation will result in invalid document structure." could be also thrown. A sample call stack is:

Telerik.Windows.Documents.Layout.LayoutBox.CreateNewFragment(Telerik.Windows.Documents.Layout.LayoutBox currentLineStartNode) 
Telerik.Windows.Documents.Layout.TableCellLayoutBox.MeasureOverrideInternal(Telerik.Windows.Documents.Model.SizeF availableSize) 
Telerik.Windows.Documents.Layout.TableCellLayoutBox.Telerik.Windows.Documents.Model.IBlockContainerLayoutBox.CallMeasureOverrideInternal(Telerik.Windows.Documents.Model.SizeF availableSize) 
Telerik.Windows.Documents.Layout.BlockContainerLayoutHelper.CheckAllFloatingBlocksAreIncluded(Telerik.Windows.Documents.Model.SizeF availableSize) 

Fix available in LIB Version 2018.1.312.

If content with DocumentLists and ListStyles respectively, is copied from Microsoft Word and then pasted in RadRichTextBox, ArgumentNullException is thrown while the lists from the DocumentFragment are fixed (FixListStyles() method). 

The exception is caught and thus, the content from the clipboard is not inserted during the copy/paste operation. In some cases, when the content is pasted again, the content is pasted.

Workaround: Replace the fragment in the clipboard with one that is already "fixed". See the attached MainWindow.cs.txt

While clicking to position the caret at the beginning of a paragraph, the caret is jumping to the previous document position and returning back to the desired one. 

Fix available in LIB Version 2017.2.627.

RadDocument instances leak when editing a document containing a field and header/footer. The StyleRepository holds a reference to a style's document element.

Fix available in LIB Version 2017.3.1002.

Implement a Page Setup dialog which allows the users to modify Margins, Layout, Page Size, etc. of the document. 

Improve the performance when multiple paragraphs are selected and deleted.

The caret (cursor) is drawn over letters. This is unpleasant, especially with small font sizes. The issue is even more noticeable when the zoom factor is bigger than 100%.

Available in LIB Version 2018.1.312.

Most of the CJK characters are not defined or don't look good in fonts not specifically designed for CJK.

Because of this it would be convenient the font to be automatically changed to MS Mincho in case the user starts writing CJK characters. 

Note that if the current font supports CJK (for example Arial Unicode MS), the font is not changed to MS Mincho.

When track changes are enabled, setting very large values for both the Top and Bottom values of Distance from text, causes an exception in ParagraphLayoutBox.

Stack trace:

{System.NullReferenceException: Object reference not set to an instance of an object. at Telerik.Windows.Documents.Layout.ParagraphLayoutBox.ArrangeOverride(SizeF finalSize) at Telerik.Windows.Documents.Layout.LayoutElement.ArrangeCore(RectangleF finalRect) at Telerik.Windows.Documents.Layout.LayoutElement.Arrange(RectangleF finalRect) at Telerik.Windows.Documents.Layout.SectionLayoutBox.ArrangeOverride(SizeF finalSize) at Telerik.Windows.Documents.Layout.LayoutElement.ArrangeCore(RectangleF finalRect) at Telerik.Windows.Documents.Layout.LayoutElement.Arrange(RectangleF finalRect) at Telerik.Windows.Documents.Layout.DocumentLayoutBox.ArrangeOverride(SizeF finalSize) at Telerik.Windows.Documents.Layout.LayoutElement.ArrangeCore(RectangleF finalRect) at Telerik.Windows.Documents.Layout.LayoutElement.Arrange(RectangleF finalRect) at Telerik.Windows.Documents.Model.RadDocument.Arrange(RectangleF arrangeRect) at Telerik.Windows.Documents.UI.DocumentPrintLayoutPresenter.MeasureOverride(Size availableSize) at System.Windows.FrameworkElement.MeasureOverride(IntPtr nativeTarget, Single inWidth, Single inHeight, Single& outWidth, Single& outHeight)} 

Steps to reproduce:
1. Enable track changes

2. Insert an image

3. Open Floating Blocks Layout Dialog

4. Choose Top and Bottom

5. Set "Distance from text" for both Top and Bottom to 2000px and click OK

Result: Exception is thrown

Additional info: Problem is also reproduced with very large images (1000 x 800 px) and small values for Distance from text.

When FlowDirection is set to RightToLeft:

<telerik:RadRichTextBox FlowDirection="RightToLeft" />

RadRichTextBox could work as system's RichTextBox - to layout the text correctly and swap the vertical scrollbar on the left side. Another option to consider is to change the default paragraph style (or 'Normal' style?) to have RTL flow.

Currently, when this property is set, the text gets reversed and the vertical scrollbar stays on the right side.

When applying a bullet/numbered list and track changes are enabled, the change of the bullet/number should be in indicated with the track changes color.

Currently the changes is only visualized as a line left of the paragraph.

When cells with borders are copied from Microsoft Excel and pasted in RadRichTextBox, some of the borders are missing depending on their type - for example double borders, but also some other types.

Inserting carriage returns in table cell until floating UI container is moved to another page causes a crash.

After further discussion within the XAML team and more research, we decided that introducing a similar property does not align with the current idea and model of RadRichTextBox. Thus, we are declining this item.

A digital signature can be used to authenticate the identity of a user and the document’s contents. 

Add a property that can control whether a table row is allowed to break across pages or not.

When specifying an image is wrapped Top and bottom and has a large distance from text (e.g. 500px top and 500px bottom) an exception in the arrange occurs.

Steps to reproduce:
- Select image and change its Wrapping style to Top and bottom. 
- Set values 500px for distance values

Currently, when a user double-clicks a word in RadRichTextBox and does not release the left button, moving the cursor drags the selected word. In most word processors the same actions extend the selection. 

Note: The same applies for triple click, which selects the paragraph.

Add support for fallback font families on import, e.g. style="font-family:trebuchet ms, helvetica".