KeyNotFoundException is thrown when loading a document with a custom bibliographic style applied.

As a workaround, you can change the current bibliographic style to one of the predefined styles before the export of the document.

...
this.radRichTextBox.CommandExecuting += RadRichTextBox_CommandExecuting;
...

...
private void RadRichTextBox_CommandExecuting(object sender, CommandExecutingEventArgs e)
{
    if (e.Command is SaveCommand)
    {
        this.radRichTextBox.ChangeBibliographicStyle(new APAFifthEditionStyle());
    }
}

Korean language input does not work correctly on Windows 11 versions after 22H2 (OS Build 22621.1265).

This is related to an update to the Microsoft Input Method Editor (IME). The workaround is to enable the "Previous version of Microsoft IME" (check the attached screenshots for the steps).

Importing a document with block-level content controls from XAML causes them to become corrupt. If you scroll to a position in which the said control is only partially visible a NullReferenceException is thrown.

A possible workaround would be to initially save the document as a DOCX (just exporting it to DOCX will not fix the issue as the information is already corrupt).

Another way to reproduce this issue:

1. Create a new document and insert a Rich Text Content Control.

2. Save the document as a XAML file.

3. Reopen the XAML file.

4. Move the caret inside the Content Control.

5. Try to insert a new line by hitting Enter - no new line is added as the content control is marked as Inline Level after the import in step 3.

Case 2: 

Create a document with TOC where the content control of the TOC contains some other inlines.