Se the attached video to reproduce.

How to reproduce: set the RadRichTextEditor.IsReadOnly property to true, focus the control, use the Ctrl + K shortcut. The InsertHyperlinkDialog will be opened.

Workaround: handle the CommandExecuting event
public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();

        this.radRichTextEditor1.IsReadOnly = true;
        this.radRichTextEditor1.CommandExecuting += RadRichTextEditor1_CommandExecuting;
    }

    private void RadRichTextEditor1_CommandExecuting(object sender, Telerik.WinForms.Documents.RichTextBoxCommands.CommandExecutingEventArgs e)
    {
        if (this.radRichTextEditor1.IsReadOnly && e.Command is ShowInsertHyperlinkDialogCommand)
        {
            e.Cancel = true;
        }
    }
}

Currently, the document won't be imported due to an exception when decoding the base64 string image source. The expected behavior is the document to be imported and the image to be shown as a missing image.

This functionality will decrease the size of the exported document.

How to reproduce: check the attached video

The bullets can have their own alignment. Implement import and export of this setting.

In MS Word, this alignment can be set through the Numbering dropdown -> Define New Number Format

The following parts are with hard coded strings and cannot be localized:

 - Insert Caption (InsertCaptionDialog): Combo boxes for label and separator
 - Paragraph Properties (ParagraphPropertiesDialog): Units of spacing and indentation values (pt)
 - Tab Stops Properties (TabStopsPropertiesDialog): The text of the tabStopsToBeClearedTextBloc
 - Cross references: reference types Figure and Table
 - TOC  and TOF: Heading and Figure, Caption labels
 - Document Ruler: Tooltips
 - FormattingColorPicker: The "No Color" string
- ManageStylesDialog shows items "Modify" and "Delete" with hardcoded text.

Create different options for pasting (keep formatting, merge formatting, use destination styles). At this point, the document default styles are not copied in the document fragment, thus their loss is observed. 

Loss of formatting is also observed when:
- copying from RadRichTextBox and pasting in Word
- copying from RadRichTextBox and pasting in RadRichTextBox in another process.
- copying from Word and pasting in RadRichTextBox

How to reproduce: check the attached video

How to reproduce:  set the page view in backstage, add a page item and set its text to be very long

Workaround: use the custom theme

How to reproduce: create a document like the one below, then try to add a comment  for an element in the paragraph with the bookmarks
Public Class Form2
    Sub New()

        InitializeComponent()

        Dim document As New RadDocument()
        Dim section As New Section()
        Dim paragraph As New Paragraph()
        Dim span As New Span("Content prior range[")
        Dim span2 As New Span("]Content after range")
        Dim readOnlyContent As New Span("READ ONLY")
        Dim rangeStart As New ReadOnlyRangeStart()
        Dim rangeEnd As New ReadOnlyRangeEnd()
        rangeEnd.PairWithStart(rangeStart)
        paragraph.Inlines.Add(span)
        paragraph.Inlines.Add(rangeStart)
        paragraph.Inlines.Add(readOnlyContent)
        paragraph.Inlines.Add(rangeEnd)
        paragraph.Inlines.Add(span2)
        section.Blocks.Add(paragraph)
        document.Sections.Add(section)

        Dim bmSection As New Section()
        Dim bmParagraph As New Paragraph()
        Dim bmSpan As New Span("Content prior bookmark[")
        Dim bmSpan2 As New Span("]Content after bookmark")
        Dim bmContent As New Span("Content in Bookmark")
        Dim bmRangeEnd As New BookmarkRangeEnd()
        Dim bmRangeStart = DirectCast(bmRangeEnd.CreatePairedStart(), BookmarkRangeStart)
        bmRangeStart.Name = System.Guid.NewGuid().ToString()
        bmParagraph.Inlines.Add(bmSpan)
        bmParagraph.Inlines.Add(bmRangeStart)
        bmParagraph.Inlines.Add(bmContent)
        bmParagraph.Inlines.Add(bmRangeEnd)
        bmParagraph.Inlines.Add(bmSpan2)
        bmSection.Blocks.Add(bmParagraph)
        document.Sections.Add(bmSection)

        Me.RadRichTextEditor1.Document = document

    End Sub
End Class

Steps to reproduce: 
1. Use the following code snippet: 
public partial class Form1 : RadForm
{
    public Form1()
    {
        InitializeComponent();
        this.WindowState = System.Windows.Forms.FormWindowState.Maximized;
    
        this.radRichTextEditor1.Document = ImportDocx(@"..\..\lorem.docx");
        this.radRichTextEditor1.LayoutMode = DocumentLayoutMode.Paged;
        this.radRichTextEditor1.ChangeSectionPageSize(PaperTypeConverter.ToSize(PaperTypes.A3));
        this.radRichTextEditor1.ChangeSectionPageOrientation(PageOrientation.Landscape);
    }

    private void radButton1_Click_1(object sender, EventArgs e)
    {
        this.radRichTextEditor1.PrintPreview();
    }

    private void radButton3_Click(object sender, EventArgs e)
    {
        this.radRichTextEditor1.Print(true);
    }	
}

Calling the PrintPreview method, the page orientation is updated in PrintSettingDialog. However, the page size is not updated correctly. As result, the printed document is not correct. 
If you call the Print method, the page size and orientation are not updated and the document is printed as in A4/Portrait instead A3/Landscape. 

Workaround:
Use RadPrintDocument: 
private void radButton2_Click(object sender, EventArgs e)
{
    RadPrintDocument radPrintDocument1 = new RadPrintDocument();         
    radPrintDocument1.AssociatedObject = this.radRichTextEditor1;
    radPrintDocument1.Landscape = true;
    PaperSize ps = new PaperSize();
    ps.RawKind = (int)PaperKind.A3;
    radPrintDocument1.DefaultPageSettings.PaperSize = ps;
    radPrintDocument1.Print();
    //this.radRichTextEditor1.Print(true, radPrintDocument1);
}

how to reproduce: check the attached video

To reproduce: add some text to RadRichTextEditor and set the Enabled property to false. You will notice that the text gets bold and blurry. 

Workaround: instead of disabling RadRichTextEditor, use the ReadOnly property.

To reproduce: try to hide the caret: 
this.radRichTextEditor1.CaretWidth = 0;

Workaround:

//Flow layout
this.radRichTextEditor1.LayoutMode = DocumentLayoutMode.Flow;
Telerik.WinControls.RichTextEditor.UI.DocumentWebLayoutPresenter webLayoutPresenter =
    this.radRichTextEditor1.RichTextBoxElement.ActiveEditorPresenter as Telerik.WinControls.RichTextEditor.UI.DocumentWebLayoutPresenter;
webLayoutPresenter.Caret.Width = 0;

//Page layout
this.radRichTextEditor1.LayoutMode = DocumentLayoutMode.Paged;
Telerik.WinControls.RichTextEditor.UI.DocumentPrintLayoutPresenter activeEditorPresenter1 = 
    this.radRichTextEditor1.RichTextBoxElement.ActiveEditorPresenter as DocumentPrintLayoutPresenter;
activeEditorPresenter1.Caret.Width = 0;

To reproduce: please refer to the attached sample project. You will notice that the exported HTML content from the left RadRichTextEditor is imported to the right and the bullets are not the same.