Hi!  Thank you for your clear and thorough post.  After following all the recommended actions in this thread with hopes that it would work for me where it did not for you, I still have the same problem. I am convinced you are right.  I just updated to the latest version of Catalina and now I can't view or print any pdf files in payroll.  I am not very computer savvy and am crying at my desk.  Luckily I work from home.  Quickbooks keeps giving me instructions for Windows. Ugh!