I looked up this issue in the forum. Found a discussion and wanted to comment. When I left to create an account, I could not find the original post. However, there was much discussion as to why one could not get the “Open File …” to get past requesting PDF Architect. Since this seems to be a rather large undertaking to determine what in the .NET framework is causing the problem, why not add a field to the Profile Edit that allows us, the user, to simply enter the name of the PDF Reader of our choice. Seems as though this would get by all of the road blocks. Even it the filename required full Path name, it would seam that a “browse” function could be implemented to make the job a bit more foolproof. I have two windows 10 laptops. On one, it does go to the default .PDF application. The other always asks about PDF Architect. The one that is not working is the most recent version as I downloaded it just before writing. The other computer that does get the default app for .PDF Files has version 2.5.