The character is visualized as '3'. The same issue is also reproducible when the content is copied from Adobe.

Right now an exception is not raised for gruop3 2d encoding.

When a pdf/a compliant document is opened in Adobe, there is a bar saying that the document is compliant with the standard. Expose such functionality in PdfViewer as well.

Loading document containing link with no destination leads to ArgumentNullException in PdfElementToFixedElementTranslator.CreateDestination method.

The current implementation relies on valid cross-reference table offsets in the PDF documents so that PDF objects are easily found and parsed. However, a mechanism for importing documents with invalid cross-reference table offsets may be implemented.

The attached project shows how to repair such documents.

When importing a document with empty pages collection an ArgumentNullException: 'Value cannot be null.
Parameter name: page', is thrown, which leads to application crash.

Workaround: Import the document using the PdfProcessing library and add an empty page:

 

The CIDFont dictionary may contain an array, describing the widths of the glyphs. If the width has a negative value an ArgumentException: 'Width and Height must be non-negative.', is thrown when the document is imported in RadPdfViewer, which leads to application crash.

An implementation of JPXDecoder should be created to allow the decompression of data encoded using the wavelet-based JPEG2000 standard.

Guidelines of how to provide a custom implementation of the JPXDecode filter can be found in the Customize Rendering section of the documentation and a sample implementation can be found in the SDK examples.

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, which leads to non-editable fields in RadPdfViewer.

When the FixedDocumentSinglePagePresenter content control is used to visualize PDF files in custom PDF viewer implementation a raise condition can be occurred leading to NullReferenceException with the following stack trace:
at Telerik.Windows.Documents.Fixed.UI.UIElementsHelper.FillPageContentElementsInPanel(Canvas container, RadFixedPage page)
at Telerik.Windows.Documents.UI.FixedDocumentSinglePagePresenter.CreateContent(RadFixedPage page)
at Telerik.Windows.Documents.UI.FixedDocumentSinglePagePresenter.PageLoader_WorkCompleted(Object sender, WorkCompletedEventArgs e)
at Telerik.Windows.Documents.Utilities.ResourceLoader.OnWorkCompleted(WorkCompletedEventArgs args)
at Telerik.Windows.Documents.Utilities.ResourceLoader.Worker_RunWorkerCompleted(Object sender, RunWorkerCompletedEventArgs e)
at System.ComponentModel.BackgroundWorker.OnRunWorkerCompleted(RunWorkerCompletedEventArgs e)
at System.ComponentModel.BackgroundWorker.AsyncOperationCompleted(Object arg)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)

The exception is thrown since the current page is unloaded while the content is being parsed.

The EI keyword defines an operator for ending the image data. When the stream contains the same sequence, the parser treats that as an end of the image data. As a result, the image and the following content cannot be properly parsed and there is missing content when the document is visualized.

The offset of the CropBox is not respected and is always treated as 0.

Workaround: Import the document with PdfProcessing, change the CropBox offsets of the pages to 0, export the modified document and then import it in PdfViewer.

They are used by the page and the XObjects drawn on it and deal with the overlaying of the colors. These groups are described on page 556 of PdfReference 1.7. 

Telerik.Windows.Zip.InvalidDataException for unknown (0xAD) compression method is thrown for some object streams.

RadPdfViewer does not read image resources defined in Form XObject elements.

Implement import of documents containing Type 3 fonts.

This happens only in scenarios when the widget has On state appearance defined and Off state appearance missing. If both appearances are missing then RadPdfViewer recalculates the appearances and the checkbox is successfully selected and deselected.

I want to draw the signature box, like in Adobe Acrobat Reader.

This is very important when the document needs more than 1 signature.

Add PrintPreview dialog visualizing the way the document is going to be printed.

Add support for interactive forms based on the Adobe XML Forms Architecture (XFA). XFA specifies an XFA resource, which is an XML stream that contains the information of the form. The format of an XFA resource is described in the XML Data Package (XDP) Specification. The XFA resource provides most of the information about the form; in particular, all form-related events such as calculations and validations.