UPDATE - After updating my 2019 QB to the latest version, I again had the problem of not being able to open 2018 with 2019 running. It would appear that there i...
The Quickbooks Tool Hub did not help, either using the Quick Fix or the Program Diagnostic Tool Options.What eventually worked for me was going to Programs & Fe...
I have the same issue with Pro 2018 and Pro 2019. I have re-installed both versions of QB and done a hard re-start on my computer, to no avail. I have the lates...