A similar scenario is not defined in the PDF specification but the widgets can be rendered as read-only fields despite the fields associated with them are missing.

At this point, the Print() method allowing the customers to silently print a document uses the PrintableAreaWidth and PrintableAreaHeight properties of the print dialog, which are read-only and cannot be changed through the API. Consider changing them with PrintTicket.PageMediaSize.

We should also consider the scenario when the client needs to print a smaller PDF page on a bigger page size. For instance, A5 page to be printed on an A4 sheet without scaling the content.

When importing documents containing Interactive FormFields with an empty collection of Normal state appearances, a NullReferenceException is thrown, which leads to non-editable FormFields in PdfViewer.

Fix available in LIB Version 2018.2.730.

Instead, we should not visualize them and they should not be interactable with the mouse.

Fix available in LIB Version 2018.2.730.

RadPdfViewer's AcroForm property ViewersShouldRecalculateWidgetAppearances should be respected when being set to true. In this case, RadPdfViewer should recalculate all widget appearances and this would resolve the issue with empty form field widgets after opening such PDF document.

When Find Next is used multiple times fast, and pages are still loaded asynchronously, sometimes NullReferenceException is thrown with the following call stack:

System.NullReferenceException: Object reference not set to an instance of an object.
   at Telerik.Windows.Documents.Fixed.Text.TextRecognizer.GetLastCharacter()
   at Telerik.Windows.Documents.Fixed.Text.TextRecognizer.IsLineBreak(Glyph glyph)
   at Telerik.Windows.Documents.Fixed.Text.TextRecognizer.ProcessGlyph(Glyph glyph)
   at Telerik.Windows.Documents.Fixed.Text.TextRecognizer.CreateTextPage(RadFixedPageInternal page)
   at Telerik.Windows.Documents.Fixed.Text.TextDocument.GetTextPage(Int32 index)
   at Telerik.Windows.Documents.Fixed.Search.KMPTextSearch.FindNext(TextDocument document, TextPosition startPosition, String searchText, Boolean matchCase, Boolean wholeWordsOnly)
   at Telerik.Windows.Documents.Fixed.Search.TextSearch.Find(String text, TextSearchOptions options)

...

The width values from the widths PDF property should be taken with priority compared to the font file calculations.

Fix available in R2 2018 SP1 release version.

Usually, the entries are on neighboring rows. However, some producers introduce some extra blank rows between entries and this causes exception in RadPdfViewer implementation.

Fix available in R2 2018 SP1 release version.

The issue is reproducible only on Windows XP. On newer versions of windows, the images are rendered as expected.

WORKAROUND: You may inherit DctDecode class in order to implement custom decoder. For instance, you may try calling 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);
    }
}

When ScaleMode is set to FitToPage scrolling the Mousewheel or pressing the Arrow Down button does not produce immediate scroll. The page is scrolled to the next page after several scroll events/button presses are introduced.

Workaround: Provide custom ScrollCommand implementation.

Currently the minimal zoom out value is 0.8% which impacts the performance while scrolling large documents.

When graphic state uses stroking text rendering mode, the glyphs are visualized with bigger stroke thickness than the expected one.

Available in LIB Version 2018.2.521.

This is reproducible when the matched result resides on different page.

Workaround: You may subscribe to the RadFixedDocument.CaretPosition.PositionChanged event and implement the scroll logic. Subscribe to PdfViewer's DocumentChanged event first if the document is not loaded.
        private void CaretPosition_PositionChanged(object sender, EventArgs e)
        {
            Telerik.Windows.Documents.Fixed.Model.RadFixedPage currentPage = this.pdfViewer.Document.CaretPosition.Page;
            int pageIndex = this.pdfViewer.Document.Pages.IndexOf(currentPage);
            this.pdfViewer.GoToPage(pageIndex + 1);
        }

Currently, we use System.Windows.Controls.TextBox for editing both TextBox and CombTextBox field types. We should implement CombTextBox editor which would allow having spaces between characters during the editing process.

Expose a button in the UI that can be used instead of Ctrl+F.

Such a button can be currently added by customizing the default toolbar. For more information, check the documentation that describes how to achieve that: https://docs.telerik.com/devtools/wpf/controls/radpdfviewer/default-ui#customizing-the-default-ui

This is reproducible when the field VariableTextProperties has zero value for font size. 

Fix available in LIB Version 2018.1.402.

An ArgumentException is thrown internally as the font name is null. However, the name is defined in the base font and can be obtained from it.

Fix available in LIB Version 2018.1.402.

Currently, RadPdfViewer uses default constant value for the font size in this scenario.

The file contains the following:
68.637 604.561 455.981 -107.996 re
72.237 604.561 l
S
Instead of the more usual
68.637 604.561 455.981 -107.996 re
S
72.237 604.561 l
S
Both are valid but the first seems to create a problem.

Fix available in LIB Version 2018.1.319.

The exception is thrown when the RadioButtonField options array contains nested arrays instead of string values.

Fix available in LIB Version 2018.1.312.