I was searching on how to fix this same problem and found this link. The more I read the more I was sure I didn't want to start using QB20. I am currently using QB 2019. I purchased 2020 on a special a couple of months ago because it also gave me the 2021 version. I have continued to use the 2019 version and plan to have my QB consultant come and install the 2021 version and do some other things to my QB that need fixing after the first of the year. 

For awhile now I have had this little window ask install now or install later. I always picked later and never had a problem until this evening when I have lots of work to do over the next few days. I have sent my consultant an email, but since this is holiday time I don't even know if he is in town. I can't uninstall and reinstall, and I REALLY don't want QB 2020. 

Any ideas how I can get my QB to work?