1. In MS Word, create a table with text in every cell, but just before the table, add a paragraph with text (you cannot reproduce the problem with an empty paragraph)
2. In the RadRichTextBox, create a new document
3. Activate Review/Track Changes
4. Copy and paste all the content from MS Word >> as a result none of the cells in the table has change tracking markup
5. If you copy only the table from MS Word (without the non-empty paragraph), it is working as expected

Having two mention providers and using the second right after using the first one actually loads the source of the first provider.

The issue is observed when the added table is preceded by a paragraph with a font size different from the default one. As the issue is caused by a broken mouse capture, the following workaround can be employed:

someRandomFrameworkElement.CaptureMouse();

someRandomFrameworkElement.ReleaseMouseCapture();

When a whole paragraph is selected and the Set Numbering Value command is executed, the numbering value of the next paragraph is changed instead of the current one.

private void radRichTextBox_CommandExecuting(object sender, CommandExecutingEventArgs e)
{
    if (e.Command is ShowSetNumberingValueDialogCommand)
    {
        this.radRichTextBox.Document.CaretPosition.MoveToPosition(this.radRichTextBox.Document.Selection.Ranges.First.StartPosition);
    }
}

Using the microsoft word,In docx document,inserting a shape,and add the text context to the shape,then save.

when radrichtextbox  open the file,the program crashed.

To reproduce:

1. Insert content spanning 3 pages
2. Ensure a single page is visualized in the viewport 
3. Start selecting from the beginning of the content till the end by dragging the mouse
4. Press Delete

The issue is a regression introduced in R3 2021 SP1.