This causes some problems if the hyperlink is edited and the document is exported and imported again.
Workaround:
private void RadRichTextBox1_DocumentChanged(object sender, EventArgs e)
{
    var document = radRichTextEditor1.Document;

    var fields = document.EnumerateChildrenOfType<FieldRangeStart>();

    foreach (FieldRangeStart item in fields)
    {
        radRichTextEditor1.DeleteAnnotationRange(item);
    }
}

If the spell checking dialog is opened when the caret is at the end of the paragraph, the spell check stops after the fist span in the paragraph after which there is a punctuation (e.g. comma or a dot).

However, if the caret is at the beginning of the paragraph (on the first misspelled word for example), everything works as expected.

When there is a Section with columns layout and it is separated with continuous section break, inserting column break in some of the columns doesn't get into account when the calculations of the available height are made.

Text in a section before continuous section break is not evenly distributed among columns when Left column type is applied.  
As a result the first column's height is bigger than the height of the second column. 

Performing Undo of bolded selection when the selection includes two tables separated by a paragraph is nesting the tables which were siblings.

When a conditional table style is applied to a table and the document is exported to RTF format, when the exported document is opened in MS Word, the FontWeight and ForeColor properties are not respected.

Examples:
If Grid Table 4 style from the gallery is applied and the document is exported and opened in MS Word, the FontWeight property is not respected and the text is not bolded.
If Grid Table 5 Dark style from the gallery is applied and the document is exported and opened in MS Word, the FontWeight and ForeColor properties are not respected.

When there is applied a local font family, the font family of the theme should be set to none. Otherwise, the font family of the elements that have a local value will be changed.

Workaround: Reset the theme font family after import: 

this.radRichTextBox.Document.Style.SpanProperties.ThemeFontFamily = Telerik.Windows.Documents.Model.Themes.ThemeFontsEnum.none;

When exporting to HTML, each two consequent spaces in a run are treated as  . However, when a style is applied to one of the spaces, the span is split and the two spaces are not considered as a pair, therefore, the HtmlFormatProvider exports them as normal spaces.

When the two spaces are the whole content of a paragraph, this paragraph is not visible when the HTML is visualized in a browser. 

When a table is the only content in a document and is copy/pasted, it is inserted in the copied table as nested. The issue is observed only when the table is the only content in the table. It is not observed when an empty paragraph is available before the table or any spacing is inserted after the table.

To workaround the issue, the selected table could be deleted before pasting.

The commands that toggle different span styles (bold, italic, underline, strikethrough) stop working after using them several times on different ranges of cells. If a single cell is selected, the span could be properly changed.

The issue is reproducible with 2013 Q1 version and newer. It is not observed with version 2012 Q1.

When a custom style is applied to a table and the document is exported to DOCX or RTF format, after importing and deleting the custom style, some properties like font size and foreground are preserved.

After inserting page break or section break the visual position of the caret is wrong. It should be at the beginning of the paragraph instead of beginning of the page. It's observed for all type of breaks except a line break. 

Section break formatting symbol is not positioned as in MS Word. 
For example, when section break is inserted in an empty document and the cursor is placed before the break, when Enter is pressed, the section break formatting symbol is moved to the next line. 
In MS Word, the section break is preserved on the same line with the paragraph symbol.

When a document has some section properties like orientation or page size and the document is printed with virtual printer, the generated PDF does not preserve the section properties. 

For example, if the document has Landscape orientation set, in the generated PDF file, the page with Landscape orientation is visualized with Portrait orientation and the text is drawn vertically.
If the document has some page size set, for example A5, in the generated PDF file, the page with size A5 is visualized as page with A4 page size.

Importing HTML document with white spaces and new lines separating the HTML elements will lead to additional intervals between words.

The width of the table cell is calculated wrongly when it is set in the CSS style and through attribute: <td style="WIDTH: 75%" width=450>First cell</td>. The Unit isn't reset while reading the attribute value as its unit is missing and it is interpreted as % because the previous value is in percent.

Importing HTML with "a:link" CSS style will be applied to the text in a bookmark. Here is example of such HTML:

<html>
  <head>
    <style type="text/css">
      a:link {
        text-decoration: underline;
      }
    </style>
  </head>
  <body>
    <a name="anchor">Anchor element</a>
  </body>
</html>

A possible workaround is to select the content between the bookmarks and apply different underline decoration. Here is example of how this could be done:

List<BookmarkRangeStart> bookmarks = document.EnumerateChildrenOfType<BookmarkRangeStart>().ToList();
foreach (var rangeStart in bookmarks)
{
    document.Selection.Clear();

    var start = new DocumentPosition(document);
    start.MoveToEndOfDocumentElement(rangeStart);

    var end = new DocumentPosition(document);
    end.MoveToEndOfDocumentElement(rangeStart.End);

    document.Selection.AddSelectionStart(start);
    document.Selection.AddSelectionEnd(end);

    RadDocumentEditor editor = new RadDocumentEditor(document);
    editor.ChangeUnderlineDecoration(UI.TextDecorations.DecorationProviders.UnderlineTypes.None);
}

document.Selection.Clear();

For example, if the document has "Times New Roman" as a default font family, the "TableNormal" style doesn't have set that property and there is a Table element in the header - the value is not properly obtained ("Verdana" is applied, which is the default value for that Span property).
The problem is observed for all default span style properties.

Workaround: Change the table style by setting the necessary properties from the default style. For example for the font family:

object documentFontFamilyPropertyValue = this.radRichTextBox.Document.Style.GetPropertyValue(Span.FontFamilyProperty);
foreach (StyleDefinition tableStyle in this.radRichTextBox.Document.StyleRepository.Where(s => s.Type == StyleType.Table && s.BasedOn == null))
{
    StylePropertyBase styleProperty = tableStyle.GetProperty(Span.FontFamilyProperty);
    if (styleProperty.ValueSource == RadValueSource.Default)
    {
        tableStyle.SetPropertyValue(Span.FontFamilyProperty, documentFontFamilyPropertyValue);
    }
}

When a list item with applied first line indent is exported to PDF, the bullets are with wrong indent (images attached)

Partial workaround: Remove the first line indent and set it as left indent in order to preserve the visualization of the document
editor.ChangeParagraphLeftIndent(paragraph.FirstLineIndent + paragraph.LeftIndent);
editor.ChangeParagraphFirstLineIndent(0);

When a table is copied (without a paragraph before it) and pasted as first element in a Section in RadRichTextBox with Track Changes enabled, accepting all changes throws (handled) InvalidCastException. Changes are not accepted.

Workaround: Attach to RadRichTextBox.CommandExecuting event, and add paragraph before the table in the document fragment in the clipboard.
private void RadRichTextBox_CommandExecuting(object sender, Telerik.Windows.Documents.RichTextBoxCommands.CommandExecutingEventArgs e)
{
    if (e.Command is Telerik.Windows.Documents.RichTextBoxCommands.PasteCommand)
    {
        if (this.radRichTextBox.Document.IsTrackChangesEnabled)
        {
            DocumentFragment documentFromClipboard = ClipboardEx.GetDocument();
 
            if (documentFromClipboard != null)
            {
                e.Cancel = true;
 
                RadDocument documentFormClipboard = documentFromClipboard.ToDocument();
 
                if (documentFormClipboard.EnumerateChildrenOfType<Table>().Count() > 0)
                {
                    Section firstSection = documentFormClipboard.Sections.FirstOrDefault();
                    if (firstSection.EnumerateChildrenOfType<Table>().Count() > 0)
                    {
                        if (firstSection.EnumerateChildrenOfType<Table>().FirstOrDefault() != null)
                        {
                            Table table = firstSection.EnumerateChildrenOfType<Table>().FirstOrDefault();
                            Paragraph paragraph = new Paragraph() { SpacingAfter = 0, SpacingBefore = 0, LineSpacing = 0, FontSize = 1 };
                            firstSection.Blocks.AddBefore(table, paragraph);
 
                            RadDocumentEditor editor = new RadDocumentEditor(this.radRichTextBox.Document);
                            DocumentFragment fragment = new DocumentFragment(documentFormClipboard);
                            editor.InsertFragment(fragment);
                        }
                    }
                }
            }
        }
    }
}