I have been having the same issue since January. Oddly, I can read the docs that I scan as pdf on my iPad but not on my Mac or PC. I receive the following message:
"Adobe Reader could not open '_____.pdf' because it is either not a supported file type or because the file has been damaged (for example, it was sent as an email attachment and wasn't correctly decoded)."
It doesn't matter if I use Safari, Chrome, etc.
I have the most up to date Adobe products.