During export operation of a document that contains signature fields the following error occurs: 

System.InvalidOperationException: 'The signature was not properly initialized for external signing. The signing delegate is missing.'

Setting the ComplianceLevel to PdfA3B and the TaggingStrategy to UseExisting when exporting a PDF document leads to the following Error reported by VeraPdf:

Specification: ISO 19005-3:2012, Clause: 6.2.11.5, Test number: 1
For every font embedded in a conforming file and used for rendering, the glyph width information in the font dictionary and in the embedded font program shall be consistent.
Glyph width 274.4140625 in the embedded font program is not consistent with the Widths entry of the font dictionary (value 272)

Resaving a document with Acrobat throws an error due to invalid Info dictionary in document trailer.

Add support for ShadingType 1.

You need to explicitly set the correct MIME type when embedding the file into the PDF. This is especially important for standards like PDF/A-3 and Factur-X, which require strict metadata and MIME type declarations for embedded files.

The default value /application/octet-stream is too generic and not compliant for XML attachments.

 

Handle the import of documents with an invalid cross-reference stream offset.

When import-export a document with embedded font(s) and FontEmbeddingType.Subset set, the subset collection is not updated, and the originally imported font is exported unmodified.

If the document contains an image that fails to be imported properly, an internal error occurs and the import process is interrupted leading to incomplete document with missing elements. 

MissingMethodException is thrown when converting a PDF stream to a PdfArray.

OutOfMemoryException is thrown when importing a large document with invalid cross-reference table.

When a Pdf document contains TextBoxFields some of which are hidden and you merge it with another document, the hidden state is reset and the field appears in the merged document:

Before:

After:

 

System.ArgumentException: 'An item with the same key has already been added. Key: Telerik.Windows.Documents.Fixed.Model.InteractiveForms.RadioButtonField'

It is reproducible when you have at least 2 pages with RadioButtonFields. The import operation goes smoothly. However, merging or removing a page after import leads to the described error.

Add support for /TR (Transfer Function) property of SMask.

The Standard Fonts are wrongly embedded when the None PdfComplianceLevel is set.

Iterate the pages of a PDF document and export each page to an image

KeyNotFoundException is thrown when importing a document with a structure element that references a page that is not part of the page collection.

ArgumentNullException is thrown when importing a restricted, AES-encrypted document.

Currently, PdfProcessing provides support for exporting images in .NET Standard: https://docs.telerik.com/devtools/document-processing/libraries/radpdfprocessing/formats-and-conversion/convert-to-image/using-image-format-provider 

Solid lines appear over dashed lines when generating PDF from SVG diagram.

Creating a document from an SVG image with a CapPathRound (stroke-linecap="round") adds unexpected lines.