The UserDict collection is not parsed and the procedures for the operators are unavailable. The exception is thrown while trying to read the font file of the Univers and Univers Bold fonts.

Internally, an ArgumenNullException is thrown, which results in missing content when the document is shown in RadPdfViewer.

All annotations are missing because ArgumentNullException is thrown while importing page annotations. The exception is handled and all non-annotation related pdf content is loaded successfully.

When importing document containing a destination which points to invalid page reference, KeyNotFoundException is thrown.

When a page is rotated its annotations are not positioned correctly. 

When the file has an annotation with a destination and this destination is missing from the destinations (Dests) collection of the catalogue, KeyNotFoundException is thrown when you try to scroll to the page where the annotation is located. A better behavior would be for nothing to happen when trying to click on the annotation leading to the destination.

When a PDF document contains images compressed with CCITTFaxDecode with applied BlackIs1 parameter, black color is visualized as white and white as black.

Default DctDecode implementation uses System.Windows.Media.Imaging.BitmapImage in order to get the image pixels. However, when the image uses some complex colorspace (for instance Separation based on CMYK) the BitmapImage is initialized with a different format and we use System.Windows.Media.Imaging.FormatConvertedBitmap in order to get the pixels in CMYK colorspace. There seems to be some issue with these calculations as the resulting image has incorrect pixels.

WORKAROUND: You may inherit DctDecode class in order to implement custom decoder and call DecodeWithJpegDecoder method from the base class as mentioned in the note of this documentation article:

http://docs.telerik.com/devtools/wpf/controls/radpdfviewer/customization-and-extensibility/customize-pdf-rendering

A sample implementation of these custom decoder may be seen below:

public class CustomDctDecode : DctDecode
{
    public override byte[] Decode(PdfObject decodedObject, byte[] inputData, DecodeParameters parms)
    {
        return DecodeWithJpegDecoder(inputData);
    }
}

Vertical lines with small length and big thickness are drawn as short horizontal lines with big StrokeThickess. This results in rendering them as big squares, which can hide parts of the content.

The text appears disordered due to wrong calculations of the glyph geometries.

It seems that the glyph outlines are rendered wrong for some specific CFF font files. For instance, the issue is reproducible with "Aleo-Light" font.

Currently, we have reproduced this issue with fonts AmnestyTradeGothic, OfficinaSanITC and OfficinaSanITC-Book.

When the first symbol in the text string array is empty the text translation is not taken into account.

/f-0-1 1 Tf
[<>-3775<0006>15<000700080002>15<0009>]TJ

This leads to a letter misplacement (too far from each other or overlapping each other).