Ok, this is what worked for me. After reading about 2021 not playing nice with 2020, I decided to uninstall 2021 temporarily. Then I went back in to QB 2020 and tested entering, adding to and deleting journal entries - all things I had problems with the system crashing over. CRASHES STOPPED. Then I tested QB 2019. I had reinstalled a previous original version of 2019 just to get the system to stop crashing when I added a journal entry or changed the account number on a check. 2019 stopped crashing under the original release so I concluded the crashing was related to the latest update I was forced to install to QB 2019. As part of my post uninstall 2021 test, I updated QB 2019 to the previously crashing current revision and tried entering, adding to and deleting journal entries. CRASHES STOPPED. So my QB 2019 and 2020 are both working properly again. I will install QB 2021 on a separate laptop away from QB 2019 and 2020 until Intuit gets this bug corrected. If you are having the trouble I did, I suggest you do the same if you can.
