How to reproduce: check the attached project and video

Workaround: create a custom RichTextEditorRibbonBar
Public Class CustomRichTextEditorRibbonBar
    Inherits RichTextEditorRibbonBar

    Protected Overrides Sub HandleFontStylePropertiesOnCurrentEditingStyleChanged()
        If Me.dropDownListFont.BindingContext Is Nothing Then
            Me.dropDownListFont.BindingContext = Me.BindingContext
        End If

        If Me.dropDownListFontSize.BindingContext Is Nothing Then
            Me.dropDownListFontSize.BindingContext = Me.BindingContext
        End If

        MyBase.HandleFontStylePropertiesOnCurrentEditingStyleChanged()
    End Sub

End Class

To reproduce:
- Open the demo application.
- Go to the Table Styles example.
- Open the TableBorders dialog from the context menu and hit reset all.

Workaround: To clear a given property, basing on some logic which determines if it should be cleared. For example
this.radRichTextEditor1.CommandExecuting += (s, e) =>
{
    if (e.Command is ChangeStyleNameCommand)
    {
        var style = this.radRichTextEditor1.Document.StyleRepository.GetValueOrNull(e.CommandParameter.ToString());
        if (style.Type == Telerik.WinForms.Documents.Model.Styles.StyleType.Paragraph)
        {
            Paragraph paragraph = this.radRichTextEditor1.Document.CaretPosition.GetCurrentParagraphBox().AssociatedParagraph;
            foreach (Span span in paragraph.EnumerateChildrenOfType<Span>())
            {
                span.ClearValue(Span.FontFamilyProperty);
                span.ClearValue(Span.FontSizeProperty);
            }
        }
    }
};

Workaround: Set the next style property for all types except the Paragraph to an empty string
foreach (var style in this.radRichTextBox.Document.StyleRepository)
{
    if (style.Type!=Telerik.Windows.Documents.Model.Styles.StyleType.Paragraph && !string.IsNullOrEmpty(style.NextStyleName))
    {
        style.NextStyleName = string.Empty;
    }
}

1. Create a document containing a style with NextStyleName:

           StyleDefinition myStyle = new StyleDefinition();
            myStyle.Type = StyleType.Table;
            myStyle.DisplayName = "My Style";
            myStyle.Name = "myStyle";
            myStyle.NextStyleName = RadDocumentDefaultStyles.HyperlinkStyleName;

            this.radRichTextBox.Document.StyleRepository.Add(myStyle);

2. Add several paragraphs and select some of them (ensure there is one using our custom style).

3. Create a DocumentFragment using the selection's CopySelectedDocumentElements

4. Convert the fragment to RadDocument and try to export it

Observed: When exporting to DOCX and XAML, the style is missing. Exporting to RTF causes KeyNotFoundException.

Expected: The style should be preserved in the exported document

Workaround: After creating the document from the fragment, ensure all needed styles are copied and available.

The new functionality should allow the developer to load custom fonts in the memory and then use them in RadRichTextEditor.

Add support for shapes, and especially for shapes with textual content. 
In OOXML, shapes are represented by the wps:wsp element, and shapes with textual content by <wps:txbx>, <w:txbxContent>.
Such shape can be added to a Word document using the Insert -> Text -> Text Box -> Draw Text Box, or through a shape's context menu -> Add Text.

Note: Do not confuse with Text/Rich Text content controls (http://feedback.telerik.com/Project/154/Feedback/Details/156478 )

How to reproduce: simply configure Polish keyboard and press [ALT GR] + [C], the added text is "©ć". The expected behavior would be to only add "ć"

Workaround: Handle the CommandExecuting event:
private void RadRichTextEditor1_CommandExecuting(object sender, Telerik.WinForms.Documents.RichTextBoxCommands.CommandExecutingEventArgs e)
{
    if (e.Command is InsertTextCommand && e.CommandParameter.ToString() == "©")
    {
        e.Cancel = true;
    }
}

To reproduce:
Format a document with tables in MSWord. For example Insert a picture to the left and a table to the right. Import the document into RadRichTextBox. You will see that the formatting is not the same.

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.

How to reproduce: check the attached video

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;
        }
    }
}

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: check the attached video

When the caret position is inside Table and a page break is inserted, the table should be split into two tables with a page break between.

Support for math type equations.