Workaround: print the document page by page:
private void radButton1_Click(object sender, EventArgs e)
{
    RadPrintDocument d = new RadPrintDocument();
    d.PrinterSettings.PrintRange = PrintRange.CurrentPage;
    d.AssociatedObject = this.radPdfViewer1;
    for (int i = 0; i < this.radPdfViewer1.Document.Pages.Count; i++)
    {
        d.CurrentPage = i;
        d.Print();
    }
}

at System.Drawing.Drawing2D.GraphicsPath.Clone()
   at Telerik.WinControls.PdfViewer.PdfElementsRenderer.RenderGlyph(Glyph glyph)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawGlyph(Glyph glyph, Graphics graphics)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawContentElement(IContentElement contentElement, Graphics graphics)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawGlyphsLayoutBox(GlyphsLayoutBox glyphBox, Graphics graphics)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawContentElement(IContentElement contentElement, Graphics graphics)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawContainer(Container container, Graphics graphics)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawContentElement(IContentElement contentElement, Graphics graphics)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawContainer(Container container, Graphics graphics)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawContentElement(IContentElement contentElement, Graphics graphics)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawPage(ContentCollection content, Graphics graphics, Matrix pageTransform)
   at Telerik.WinControls.UI.RadFixedPageElement.pageRenderer_DoWork(Object sender, DoWorkEventArgs e)
   at System.ComponentModel.BackgroundWorker.OnDoWork(DoWorkEventArgs e)
   at System.ComponentModel.BackgroundWorker.WorkerThreadStart(Object argument)
   at System.Drawing.Drawing2D.GraphicsPath.Clone()
   at Telerik.WinControls.PdfViewer.PdfElementsRenderer.RenderGlyph(Glyph glyph)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawGlyph(Glyph glyph, Graphics graphics)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawContentElement(IContentElement contentElement, Graphics graphics)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawGlyphsLayoutBox(GlyphsLayoutBox glyphBox, Graphics graphics)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawContentElement(IContentElement contentElement, Graphics graphics)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawContainer(Container container, Graphics graphics)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawContentElement(IContentElement contentElement, Graphics graphics)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawContainer(Container container, Graphics graphics)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawContentElement(IContentElement contentElement, Graphics graphics)
   at Telerik.WinControls.PdfViewer.FixedPageRenderer.DrawPage(ContentCollection content, Graphics graphics, Matrix pageTransform)
   at Telerik.WinControls.UI.RadFixedPageElement.pageRenderer_DoWork(Object sender, DoWorkEventArgs e)
   at System.ComponentModel.BackgroundWorker.OnDoWork(DoWorkEventArgs e)
   at System.ComponentModel.BackgroundWorker.WorkerThreadStart(Object argument)

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

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.

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. 

how to reproduce: check the attached file

workaround: resize the form

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);

How to reproduce: check the attached project

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

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.

When there is no ToUnicode CMap, the text from the Simple Font instance should be extracted by mapping the glyph name to its corresponding charcode according to Adobe Glyph List. Additionally, the Differences array should be included in these calculations when there is custom encoding. The current implementation of RadPdfViewer makes ToString to the original char id byte value which leads to wrong characters. 

The events should provide information as to when a page is about to be rendered and when it is displayed in the control.

Please refer to the attached gif file and sample project. When you hide the overflow button with the first pixel, although it is indicated as Visible, it is actually not shown.

Workaround: Timer timer = new Timer();

private void commandBarStrip_ItemOverflowed(object sender, EventArgs e)
{
    timer.Interval = 100;
    timer.Tick += timer_Tick;
    timer.Start();

}

private void timer_Tick(object sender, EventArgs e)
{
    timer.Tick -= timer_Tick;
    var commandBarStrip = this.radPdfViewerNavigator1.CommandBarElement.Rows[0].Strips[0];
    commandBarStrip.OverflowButton.Visibility = ElementVisibility.Visible;
    timer.Stop();
}