Thunderbird stops responding at least twice each time I open it, especially bad when first starting the computer. I have to quit the program in the task manager in order to close and try again. Version 78.4.0 running on Windows 8.1. This problem seems to get worse with each new Thunderbird update. Any ideas how to get this to stop? No such problems on my Windows 10 machine. Operating system is up-to-date.