Currently, there is an SDK example (https://github.com/telerik/xaml-sdk/tree/master/RichTextBox/WindowsMetafileFormatImageDecoder) showing how to implement a custom decoder that can import WMF and EMF images. We could integrate this decoder in the source code and enable the users to import their documents that contain such type of images out-of-the-box. 

Available in R1 2017 Official Release Version.

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.

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. 

Stretching the text is done by modifying the Scale Property of the Character Spacing properties. In the Office Open XML specification, it is represented by the <w:w w:val="300"/> tag. 

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.

ArgumentOutOfRangeException is thrown when replacing all (Replace All button is clicked from the FindReplace dialog) occurrences of given text if the replace text is with smaller length than the searched text. 

For example if we have the following text written in the RadRichTextBox: "Some Text" and we want to replace all occurrences of "Some Tex" with "AA" (open find and replace dialog and click ReplaceAll button), the exception occurs

Workaround: Change the FindReplaceDialog with a custom one (see how in this SDK demo - https://github.com/telerik/xaml-sdk/tree/master/RichTextBox/CustomFindReplaceDialog ). In the new custom dialog, buttonReplaceAll_Click event handler, change the initialization of the 'startFindPosition' variable to be in the body of the while loop.

Available in LIB Version 20181.205.

There is no command or API in the editor for deleting paragraph, but there is such for, for example, deleting table. 

Currently list styles cannot be removed from the document model.

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 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 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.

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

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. 

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 one column section is selected, "Line between" and "Equal column width" checkboxes should be disabled.

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.

When the Chinese IME is used with Microsoft Pinyin input, FatalExecutionEngineError is thrown in the FocusCaret() method of DocumentWebLayoutPresenter. The exception is not reproducible in Paged layout mode.

In RichTextBox, only the background (the fill attribute) is supported and the val and color attributes (determining the pattern and its color) are not respected while importing.

In some cases when an image is copied from an external source and pasted in the rich text box, the image is not displayed. This is caused by the Clipboard.GetImage() method used internally by the control. 

To work this around, you can subscribe for the CommandExecuting event of RadRichTextBox and manually get the image from the clipboard.

private void Rtb_CommandExecuting(object sender, Telerik.Windows.Documents.RichTextBoxCommands.CommandExecutingEventArgs e)

{
	PasteCommand command = e.Command as PasteCommand;
	if (command != null && (Clipboard.GetData("DeviceIndependentBitmap") != null))
	{
		//Get the image stream from the clipboard.
		//You can check the following blog post for an approach which you can use to get the image properly:
		//https://www.thomaslevesque.com/2009/02/05/wpf-paste-an-image-from-the-clipboard/
		this.radRichTextBox.InsertImage(imageStream, "jpeg");
		e.Cancel = true;
	}
}