According to PDF format specification, there are three valid encoding name values (MacRomanEncoding, MacExpertEncoding and WinAnsiEncoding). There are documents that instead of skipping the optional Encoding property, are writing invalid /NULL name value in the font dictionary. Currently, in this invalid document scenario RadPdfViewer throws and catches Exception and this results in missing text content. 

We may handle this invalid document scenario by ignoring the invalid Encoding value.

How to reproduce: check the attached project

Workaround: manually unload the document before disposing the control, the attached project includes a solution

How to reproduce: check the attached video
a slight cut off can also be observed with the ControlDefault and the TelerikMetro themes

Workaround: 
CommandBarDropDownList dropDownList = this.radPdfViewerNavigator1.CommandBarElement.FindDescendant<CommandBarDropDownList>();
dropDownList.MinSize = new Size(72, 22);

The exception is thrown during "Put" operator execution.

how to reproduce: check the attached file

workaround: resize the form

This is not quite a valid PDF file scenario according to PDF file specification. However, we may try handling it in order to show the correct number of pages. When the kid is of type Pages, it should be added to the pages traversal recursion only the first time it is met.

The observed issue is demonstrated in the attached image. 

To reproduce:
Print the attached document with the MS Xps printer or PrimoPDF. 

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

To reproduce:

public Form1()
{
    InitializeComponent();

    this.radPdfViewer1.DocumentLoaded += radPdfViewer1_DocumentLoaded;
}

private void radPdfViewer1_DocumentLoaded(object sender, EventArgs e)
{ 
    var pdf = (RadPdfViewerElement)sender;
    var doc = new RadPrintDocument();

    doc.AssociatedObject = pdf.ElementTree.Control as RadPdfViewer; 
    doc.PrinterSettings.PrintRange = System.Drawing.Printing.PrintRange.SomePages;
    doc.PrinterSettings.FromPage = 2;
    doc.PrinterSettings.ToPage = 1;
    doc.PrinterSettings.PrintFileName = @"..\..\Once upon a time.pdf"; 
    pdf.Print(showPrinterSettings: false, document: doc);
}

Workaround: check FromPage  before printing.

There is opportunity to further optimize the caching mechanism of the image sources, which will reduce the memory consumption. The fast scrolling in a document containing big images could lead to an OutOfMemoryException.
Openining very large images as well. 

RadPdfViewer can not display annotated PDF file
 Kindly,i used VintaSoft SDk to Annotate PDF File, File is annotated successfully and i can open it with Adobe Reader and see annotations is added to it
 but while i try to view annotated PDF file using RadPDFViewer File will displayed without annotations ,only original content displayed.
Kindly find my attached AnnotatedPDFfile To be loaded in RadPDfViewer

RadPdfViewer can not display annotated PDF file
 Kindly,i used VintaSoft SDk to Annotate PDF File, File is annotated successfully and i can open it with Adobe Reader and see annotations is added to it
 but while i try to view annotated PDF file using RadPDFViewer File will displayed without annotations ,only original content displayed.
Kindly find my attached AnnotatedPDFfile To be loaded in RadPDfViewer

Workaround: 

public Form1()
{
    InitializeComponent();

    string pdfFilePath = Path.Combine(Application.StartupPath, "testfile1.pdf");
    radPdfViewer1.LoadDocument(pdfFilePath);

    this.radPdfViewer1.PdfViewerElement.VScrollBar.ValueChanged+=VScrollBar_ValueChanged;
}

private void VScrollBar_ValueChanged(object sender, EventArgs e)
{
    this.radPdfViewer1.PdfViewerElement.InvalidatePages();
}