Sorry for the delay in response.
Please refer to the following links which discuss the similar issue:
Feel free to update this discussion if you need any further help.
None of the forums above resolves the issue "There was an error opening this document. The file is damaged and could not be repaired". I run a current version of Adobe Acrobat Pro with Mac OS High Sierra 10.13.3. Recently I have been getting this error message on files I receive via Mac Mail. I can't believe that every file I receive from many different sources is corrupted. Could someone please offer a solution.
It's possible your email server is causing this. To check it, open one such file in a plain-text editor.
What are the first couple of lines you see there?
Anyway, if that's what Acrobat is saying then there's nothing you can do to fix it with it.
You would need some other tool to do it, if it's at all possible.
Thank try67, unfortunately, it hasn't opened in a text editor either. Thank you for your contribution
How do you open or save the attachment in macOS Mail? From what you describe, it sounds like you are ending up with a zero byte long file (you can confirm that by right-clicking/Ctrl-clicking the file in Finder, and then selecting "Get Info". This will report (among other things) the file size.
After a lot of deleting and reinstalling, it is behaving well. Thank you for your input, greatly appreciated.