for some days, PDF file assignment with PDF-XChange Editor seems to be broken for me.
I can still assign the opening of PDF files per default to other applications, but not to PDF-XChange Editor. It neither works via the "Open With -> Choose Other App" context menu in Windows, nor via the corresponding File Assignment setting in PDF-XChange Editor, and also not by using the "Standard Programs" function of Windows 10 like described here:
https://www.tracker-software.com/knowledgebase/264-I-have-a-problem-with-File-Associations-and-making-PDF-XChange-EditorViewer-the-default-PDF-Viewer
I can't even open PDF files directly by right-clicking and selecting "Open with -> PDF-XChange Editor". In this case nothing happens at all.

I could imagine that some entry in the registry is defective.
Thanks for any hints on how this could be fixed.
Kind regards
David