I have an 2 Excel files, password protected, that will not open. After
several hours of research, it appears this has happened many times to other
people. But, I am unable to find a solution I understand.

As I understand it, this is NOT a corrupt file as stated in the error
message but has something to do with a user certificate (or something like
that).

Does anybody have an answer on how to get this file opened?

HELP