From the PDF Specification: "An ink annotation represents a freehand “scribble” composed of one or more disjoint paths. When opened, it displays a pop-up window containing the text of the associated note."

Table cell content is not displayed after PDF export if cell Preferred Width is too small.

Workaround: Make cell Size(Preferred Width) big enough for the contents to fit.

Support for validating signature fields signed with signatures that are encoded in ETSI.RFC3161 encoding should be added.

Currently, when invoking the Signature`s TryValidate() method an exception is thrown: NotSupportedException: 'No signature validation handler was found for the subfilter: ETSI.RFC3161'

When calling a PDF export in a high-concurrency environment the internal state can get corrupted because it uses a non-thread safe collection internally.

Sample code:

void WriteToPdf(RadFlowDocument document, Stream outputStream) {

   PdfFormatProvider pdfWriter = new() {};

   pdfWriter.Export(document, outputStream);
}

When calling it like this:

Parallel.ForEachAsync(listOfDocuments, (document, _) => {
   WriteToPdf(document, Stream.Null);
});

An exception may occur:

System.InvalidOperationException: Operations that change non-concurrent collections must have exclusive access. A concurrent update was performed on this collection and corrupted its state. The collection's state is no longer correct.
   at System.Collections.Generic.Dictionary`2.FindValue(TKey key)
   at Telerik.Windows.Documents.Fixed.Model.Fonts.FontsRepository.TryCreateFont(FontFamily fontFamily, FontStyle fontStyle, FontWeight fontWeight, FontBase& font)
   at Telerik.Windows.Documents.Flow.FormatProviders.Pdf.Utils.Extensions.CopyPropertiesFrom(CharacterProperties fixedProperties, PdfExportContext context, CharacterProperties properties)
   at Telerik.Windows.Documents.Flow.FormatProviders.Pdf.Export.PdfExporter.CreateListLevel(ListLevel flowLevel)
   at Telerik.Windows.Documents.Flow.FormatProviders.Pdf.Export.PdfExporter.CreateList(List flowList)
   at Telerik.Windows.Documents.Flow.FormatProviders.Pdf.Export.PdfExporter.ExportDocument(RadFlowDocument document, RadFixedDocumentEditor editor)
   at Telerik.Windows.Documents.Flow.FormatProviders.Pdf.Export.PdfExporter.ExportInternal()
   at Telerik.Windows.Documents.Common.FormatProviders.FormatProviderBase`1.Export(T document, Stream output)
   at xxxxx.Application.Common.PdfGeneration.PdfWriter.WriteToPdf(RadFlowDocument document, Stream outputStream) 

The state is then corrupted forever, until the application is restarted.

Realistic scenario where this is also reproduced: Web application that generates PDFs and is called concurrently.

InvalidOperationException Cannot find the "endstream" keyword with a specific file.

According to the PDF Specification:

A stream consists of a dictionary followed by zero or more bytes bracketed between the keywords stream and endstream:

dictionary
stream
… Zero or more bytes …
endstream

InvalidCastException is thrown when a name start character is followed by a literal string start character.

System.InvalidCastException: Unable to cast object of type 'Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Types.PdfInt' to type 'Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Types.PdfName'.