Although Lab color space is currently unsupported, the provider should not throw exceptions that break the whole file import.

Implement API for adding document outline (a.k.a bookmarks).

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.

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 there is long text that is out of the used cell range area, this text should be included in page splitting calculations.

Also, when a cell has text that overflows its width, the text is again clipped by the cell boundaries and is not visible in the exported PDF. In a similar case Excel exports the surrounding cells to ensure that the content is visible.

Workaround: Extend the used cell range to include all the cells which the text content spans.

The data validation rule should have values for formula1 and formula2 elements, which define the start and end values for a range to validate between. When such values are missing, a NullReferenceException is thrown on import and the document cannot be imported.

When the worksheet contains many formulas which use large ranges (e.g. covering 50000 cells) as arguments and these formulas have to be calculated, this causes OutOfMemoryException. 

The CropBox is currently not supported by RadFixedPage class and is not preserved on an Import-Export scenario with PdfFormatProvider. CropBox is also not supported by PdfPageSource class and it is not preserved by using PdfStreamWriter as well. This property should be implemented in both scenarios.

Add APIs for creating and manipulating Chart objects.