On Thu, 01 Apr 2021 17:35:18 -0400, micky
wrote:

It's labeled a PDF file, but it it won't display as a pdf file, or at
all, in either of two pdf readers.

So I rename it to be an .exe file. Then it won't run "on this
computer", windows 10.

Put it back to PDF and try to open it in Word. Sometimes that can open
a file Adobe thinks is corrupt (not exactly a PDF)
You can open it in Notepad and see if the first 4 bytes are
"%PDF"