Import HTML where the image does not have a closing tag. Here are the valid closing ways: html - How to close <img> tag properly? - Stack Overflow

Background properties do not inherit, but the parent element's background will shine through by default because of the initial 'transparent' value on 'background-color'.

HTML content:

The result when exported to DOCX/PDF:

Workaround: set the style directly to the <ul> element:

The margin property sets the margins for an element, and is a shorthand property for the following supported properties:

This element represents a multi-line text input control and can be mapped to content control. 

In the document produced by the mail merge, the general formatting applied is not respected and the value is in its default format. 

When we have Document properties set (no Section properties set) and the \sectd control word is missing the Document properties are not respected.

From the RTF Specification: When we have Section properties set the \sectd resets the values to that specified by the Document properties. But when we don't have Section properties set and the \sectd is missing we should inherit the values specified by the Document properties

The styles that are declared inside the body selector should be applied to the whole document content if another styling is not specified. However, during the import, HtmlFormatProvider doesn't respect these definitions.

The line-height of the paragraph should be applied to the spacing before and after as well.

When exporting a document containing a Field that has no Separator set the content after this field is omitted.

According to the OOXML Specification, the fldCharType value separate is optional. 

The exception is thrown at Telerik.Windows.Documents.Core.Data.ValueMapper`2.GetToValue(TFrom value) with message 'System.InvalidOperationException: 'Not supported from value: 16''

KeyNotFoundException while exporting to HTML document containing single list whose first level has RestartAfterLevel=0.

 Exception trying to import HTML that contains width with an empty value. For example:

Wrong numbering position when a paragraph contains numbering in the style and a page break

When the inline image has only a width set the image size is wrongly calculated when converting to PDF

When importing HTML with image dimensions defined in inches, they are incorrectly recognized as being in pixels.

Add support for Microsoft Office Word 2003 XML Format, WordProcessingML and WordML formats

Exception when exporting empty table to HTML.

When replacing a string within a run that is not the first element in the paragraph an unexpected behavior occurs.

These are the known cases:

• System.ArgumentOutOfRangeException: 'Index and length must refer to a location within the string. Parameter name: length'
• System.InvalidCastException: 'Unable to cast object of type <<type>> to type 'Telerik.Windows.Documents.Flow.Model.Run'.'
• Shifted text.

The exception is thrown during the exporting of the document with the following stack trace:

  Telerik.Windows.Documents.Flow.FormatProviders.Docx.Model.Elements.Styles.ShadingElement.FillAttributes(IPropertiesWithShading properties)
   at Telerik.Windows.Documents.Flow.FormatProviders.Docx.Model.Elements.Document.RunPropertiesElement.OnBeforeWrite(IDocxExportContext context)
   at Telerik.Windows.Documents.FormatProviders.OpenXml.Model.Elements.OpenXmlElementBase`3.OnBeforeWrite(IOpenXmlExportContext context)
   at Telerik.Windows.Documents.FormatProviders.OpenXml.Model.Elements.OpenXmlElementBase.Write(IOpenXmlWriter writer, IOpenXmlExportContext context)
   at Telerik.Windows.Documents.FormatProviders.OpenXml.Model.Elements.OpenXmlElementBase.Write(IOpenXmlWriter writer, IOpenXmlExportContext context)
   at Telerik.Windows.Documents.FormatProviders.OpenXml.Model.Elements.OpenXmlElementBase.Write(IOpenXmlWriter writer, IOpenXmlExportContext context)
   at Telerik.Windows.Documents.FormatProviders.OpenXml.Model.Elements.OpenXmlElementBase.Write(IOpenXmlWriter writer, IOpenXmlExportContext context)
   at Telerik.Windows.Documents.FormatProviders.OpenXml.Model.Parts.OpenXmlPartBase.Export(IOpenXmlWriter writer, IOpenXmlExportContext context)
   at Telerik.Windows.Documents.FormatProviders.OpenXml.Model.Parts.OpenXmlPartBase.Export(Stream stream, IOpenXmlExportContext context)
   at Telerik.Windows.Documents.FormatProviders.OpenXml.Export.OpenXmlExporter`2.ExportPart(PartBase part, TContext context)
   at Telerik.Windows.Documents.FormatProviders.OpenXml.Export.OpenXmlExporter`2.Export(Stream output, TContext context, OpenXmlExportSettings settings)
   at Telerik.Windows.Documents.Flow.FormatProviders.Docx.DocxFormatProvider.ExportOverride(RadFlowDocument document, Stream output)
   at Telerik.Windows.Documents.Common.FormatProviders.FormatProviderBase`1.Export(T document, Stream output)

HtmlFormatProvider: The table borders are not set correctly when more than one class contains the borders settings