After signing a document using the PdfProcessing library and the document is loaded in Adobe Acrobat an error is shown when the signature widget is clicked:
Error during signature verification.  

Adobe Acrobat error.
Expected a dict object.

Allow the customers to insert DWG files in the PDF documents.

By specification, the InteractiveForm fields can have the same name if they are descendants of a common ancestor. Such fields are different representations of the same underlying field; they should differ only in properties that specify their visual appearance. When such a document is imported an ArgumentException: 'An item with the same key has already been added.' is thrown.

When importing color space defined as an external resource name, a NotSupportedColorSpaceException: 'CS0 color space is not supported.' is thrown.

For example, importing URI Action with invalid mailto URL scheme - mailto:***@***.**(E-mail), throws UriFormatException: 'Invalid URI: The hostname could not be parsed.'

Line annotation displays a single straight line on the page. When opened, it displays a pop-up window containing the text of the associated note.

A free text annotation displays text directly on the page. Unlike an ordinary text annotation, a free text annotation has no open or closed state; instead of being displayed in a pop-up window, the text is always visible.

By specification, the document AcroForm contains fields with no parents. However, some documents may have child fields in the AcroForm. This leads to ArgumentException when importing the child and parent fields - 'An item with the same key has already been added.' since the child field is added twice.

RadPdfProcessing cannot find startxref keyword at the end of a document if the document contains many zero bytes at its end. NotSupportedException is thrown with "Startxref keyword cannot be found" message. 
Workaround: Trim the ending zero bytes before loading the document to PdfProcessing. Example showing this approach can be found in the following KB article:
http://www.telerik.com/support/kb/winforms/details/notsupportedexception-startxref-keyword-cannot-be-found-when-loading-pdf-file-in-radpdfviewer-for-winforms

By specification the last line of the file contains only the end-of-file marker, %%EOF. When importing document with missing EOF, InvalidOperationException: 'Stack empty', is thrown.

This request is to ask that the development team review the code inside the Documents for refactoring to see if certain things can be reduced (like Generics).

 

When using the Telerik UI for Xamarin and referencing the UI.for.Xamarin NuGet package, the assembly reference for the Telerik.Documents.Fixed.dll is added to the project. This increases the amount of code that is compiled when the Linker is only set to SDK only, thus breaking AOT compilation with LLVM enabled.

 

A few addition insights:

 

- When the project cannot set the Linker to SDK and User Assemblies

- When individually referencing DLLs for only what the project uses is an insufficient solution

- When installing sub-packages like Telerik.UI.for.Xamarin.DataGrid is an insufficient solution.

 

 

Thank you.

By specification the explicit destinations define a required page property. However, some documents contain definition for destinations with null page value, which causes an ArgumentNullException on import.

When a document is exported with a cross-reference stream, the stream is missing the required according to the specification Length property. Although most of the viewers open the document without any issues, some cannot. Such documents cannot be opened in MS Edge.

The case is invalid according to the specification but all readers manage to open the document and allow editing its fields. The document can be also opened in RadPdfViewer but without the fields and the widgets.

Exported protected document containing SignatureField can not be opened even if the correct password is used. The same behavior is reproduced with empty document (without pages).

Implement functionality to support scenario when a document which already has a signature to be signed again or add two or more signatures.

The appearance dictionary specifies how the annotation is presented visually on the page. If the appearance missing or is empty in PDF document NullReferenceException is thrown on import. 

Currently, signature flags, represented by the 'SigFlags' optional entry, are not imported and exported, and there is no API for setting them.
As a result, documents signed with RadPdfProcessing (or with RadPdfViewer) appear in Adobe Reader without the blue document message bar at the top (the analogue of the RadPdfViewer's SignaturePanel).

If the API is supported, setting the flag to 1 or 3 would ensure that the message bar would be visualized in Adobe Reader.

When importing document with predefined ToUnicode CMaps (e.g. Identity-H), an InvalidCastException is thrown with cause: 

Unable to cast object of type 'Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Types.PdfName' to type 'Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Elements.CMaps.ToUnicodeCMap'.

When documents are exported to PDF, the creation date and modification date are not expected, or, when the time zone is with negative offset, the documents are invalid (detected by validation tools).