I can't open files because it is either not a supported file type or because the file has been damaged

[elenal20794813]

Adobe Acrobat Reader could not open 'ACC 402 Syllabus (Suh).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).

I have Mac Sierra 10.12. .. I have updated and reinstalled, nothing works.

Please help

[try67]

There's not much you can do about it if Reader can't open the file. How did you get it?

[elenal20794813]

The interesting part that files downloaded from university cannot be opened, others works fine.

[~graffiti]

How are you "downloading" the files exactly? Clicking a link in a web browser maybe? If so, what browser? If not, give us the steps you take to get the pdf file.