The exception is caused by the charts import which is not implemented for WordsProcessing but the processing tries to import the charts part and process it.

The property controls whether a paragraph should be rendered at least partially on the same page with the following paragraph when the document is shown in page view mode.

An index lists the terms and topics that are discussed in a document, along with the pages that they appear on. 

The construct <link rel="stylesheet" href="main.min.css" /> doesn't raise the HtmlImportSettings.LoadFromUri event on import, as we currently require type="text\css" to be specified explicitly.

HtmlFormatProvider does not maintain all the whitespaces on import even though {style="white-space: pre;"} was set.

It should support {style="white-space: pre-wrap;"} as well.

It can eventually be extended to support all the property's values: normal|nowrap|pre|pre-line|pre-wrap|initial|inherit.

The HtmlFormatProvider currently doesn't support borders for p elements.
There is a ParagraphBorders property in the model Paragraph class, but it isn't implemented in the HTML import. Also, ensure that the borders applied on div elements are preserved.

A paragraph containing multiple Hyperlinks inside Fields with missing End FieldCharacter, leads to OutOfMemoryException: 'Exception of type 'System.OutOfMemoryException' when exporting to PDF.

Workaround: Iterate all FieldCharacter instances and move any End FieldCharacter instance to paragraphs with Start FieldCharacters. See the attached project.

Provide support for Track Changes.

Such tags are not supported in RtfFormatProvider and while skipping them, there might be fields that are not properly imported. This can lead to issues while exporting the document. If the document is re-saved using MS Word, the HTML-related tags are removed and the content can be properly imported with WordsProcessing.

Create a feature that allows the RadWordsProcessing to split RadFlowDocument.

Workaround: DocumentElementImporter can be used to prepare a document element from the source document for import into the target document

According to the HMTL specification, the width and height attributes of an img tag has unsigned long values. When a width or height values with a unit suffix is imported, e.g.: 50%, FormatException: 'Input string was not in a correct format.' is thrown.

Hyperlinks created via HtmlFormatProvider are not properly exported to PDF and cannot be clicked.

When the document contains an image that is defined as an external resource but is not available in the specified location and cannot be found, a KeyNotFoundException is thrown. Handle this exception and replace the missing image with a default one for such cases. Consider exposing an option to notify the user about this error.

RtfException "Group level reached negative value" is thrown when a document with an image defined as a resource but not found is imported and then exported to RTF

When the imported html contains an attribute of the type width="", Wordsprocessing throws ArgumentException and does not import the document. 

Importing an image from HTML with URI as a source, which has applied only width or height and exporting it to PDF (which forces getting the image data so it can be drawn) leads to an incorrect value of 1 (a default value) for the dimension that is not specified.

When the document contains an image with extension, which is not among the supported ones, a KeyNotFoundException is thrown during Import.

An ArgumentException is thrown when importing HTML containing standard and non-standard pseudo classes or pseudo elements. The concreete scenario is the following: 
.myclass::-webkit-scrollbar or .myclass::-ms-expand

The message of the exception is similar to this: "Unexpected character found at position [X]: ".. scrollbar::>>-<<webkit-scrollbar"". 

When DefaultTabStopWidth of the document is zero, the export to PDF leads to infinite loop which causes the application to freeze.

Workaround: 
Set the DefaultTabStopWidth with non-zero value:

Implement support for pictures with references represented with the r:link attribute in the schema.