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

Currently, Tab selects the next control.

Attached is sample PDF document. 

When an image is actually consisting of a sequence of smaller images, sometimes white lines appear between the smaller images.

When clicking on link annotations pointing to destinations in the document, and the "Fit one full page to window" mode is activated, the document is not scrolled exactly to the destination.

The issue can be reproduced only in Single Page Presenter mode and when the Top and Left values of the passed parameter are greater than 0.

The problem can also be observed by invoking directly GoToDestination method, as the problem is inside it.

Watermark does not look correctly and the page margins are not valid for the very small paper sizes.

When saving Form Fields in document defined with linearized PDF structure, it produces a document that fails to open in Edge.

When the Interactive Form Fields are in read-only mode, the user should not be able to change the value of the field. The associated Form Field widgets should not interact with the user, e.g. they should not respond to mouse clicks or change their appearance in response to mouse motions.

Tint transformation function is used to transform Device N color in Alternate colorspace. 

To reproduce: please run the attached sample project. If you reload the document, the horizontal scrollbar is not shown.

Workaround:
        public RadForm1()
        {
            InitializeComponent();

            this.radPdfViewer1.FitToWidth = false;
            this.radPdfViewer1.ViewerMode = Telerik.WinControls.UI.FixedDocumentViewerMode.None;
            this.radPdfViewer1.EnableThumbnails = false; 
            this.radPdfViewer1.DocumentLoaded += radPdfViewer1_DocumentLoaded;
            this.radPdfViewer1.LoadDocument(@"..\..\Go Air - Himanshe Ajeet Dubey - 17-01-2018 - Ranchi to Mumbai.pdf");
            Application.DoEvents();
        }

        private void radPdfViewer1_DocumentLoaded(object sender, EventArgs e)
        {
            Application.DoEvents();
            this.radPdfViewer1.FitToWidth = true;
        }

This exception seems to be related to AES algorithm PaddingMode property. 

Please refer to the attached sample screenshot demonstrating how the document look in Adobe and in RadPdfViewer.

This is reproducible for images with FlateDecode and predictor value in the range between 10 and 15. As an example you may take a look at the DecodeParms property in the following image PDF dictionary:

<< /BitsPerComponent 8 /ColorSpace /DeviceRGB /DecodeParms << /BitsPerComponent 8 /Colors 3 /Columns 1024 /Predictor 15 >> /Filter /FlateDecode /Height 2868 /Subtype /Image /Type /XObject /Width 1024 /Length 1236707 >>

structure
The hierarchical document structure is a means to describe the PDF document structure, which is currently not supported. See 10.6.1 Structure Hierarchy on 856 page of the PDF specification for details.
This document structure is an alternative to the standard PDF structure and most non-Adobe software does not support it.

The document might have been created with Adobe software like Adobe LiveCycle Designer. Very often the document contains some fallback text in the standard PDF structure like:
"Please wait... If this message is not eventually replaced by the proper contents of the document, your PDF viewer may not be able to display this type of document."
"The document you are trying to load requires Adobe Reader 8 or higher. You may not have the Adobe Reader installed or your viewing environment may not be properly configured to use Adobe Reader. For information on how to install Adobe Reader and configure your viewing environment please see  http://www.adobe.com/go/pdf_forms_configure."
"For the best experience, open this PDF portfolio in Acrobat X, Reader X, or later."

Use the attached pdf document and launch the PdfPrintPreviewDialog. As it is demonstrated in the gif file, the preview dialog moves the pages slower than the pdf viewer itself.

Expected behavior: the performance for navigating the pages should be at least identical.

This is the result with R3 2022:

 

 

This is the result with R2 2023 SP1:

 

If the DataError is handled, you can detect what kind of internal errors occur. The document is loaded successfully at the end. If the thumbnails menu is hidden, the load time is much faster.

The selection position is wrong when each character is drawn with PDF operators.

Improve Error Handling for PdfRadViewer during document import (BackgroundWorker)