A page with a negative value rotation is exported as a blank image.

Workaround: Use only the Enum Rotation values (Rotate0, Rotate90, Rotate180, Rotate270).

Currently, when registering *.otf font file with FontsRepository.RegisterFont method an exception is thrown during the font creation. 

WORKAROUND:  The font file may be converted to TTF format (*.ttf) which is successfully registered. This conversion may be achieved with FontForge by opening the font file and then choosing File -> Generate Fonts -> TrueType -> Generate. More information on FontForge program may be found here: https://fontforge.github.io/en-US/

PdfProcessing: Handle merge of documents containing fields with the same invalid name.

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.

NumberedHierarchical list type has inconsistent indentation after bullets.

When exporting a document with the .NET Framework implementation, only subsets of the used fonts are embedded in the document.

The visual fill element is not exported to pdf:

Only the text part is present.

Import the document with RadSpreadProcessing and export it PDF format. You will notice that the cell value is displayed in the exported PDF document while in the Excel file it is hidden due to the custom format:

Merge two documents (use the attached ones) that already have embedded files with the same names.

Observed: 

A strange symbol is added as a name when embedding a file with an empty string as its name argument.

For example exporting the text "\uD83D\uDE0A" with "Segoe UI Symbol" font family should export a single smiling face. Instead the characters are skipped during the export as PdfProcessing is trying to export them as separate char values ("\uD83D" and "\uDE0A") and the font does not contain glyphs corresponding to these char codes.