oleh Juraj Mäsiar (Pengembang) pada Feb. 11, 2021 · tautan permanen

Well, the new addons are build using the new Web-extension API so this is most probably related to the crashing extension process. I don't think the old addons are using that (but they will stop working in the future probably in the next major release in September).

Anyway, if restarting PC doesn't help and reinstalling addons doesn't help either (make sure to restart Thunerbird after uninstalling), then I'm out of ideas.
You can try to install Thunderbird Beta but it will use a new profile so you would have to setup everything again.

I hate this random issues after updates... it's just frustrating because it should fix issues, not introduce new one...

Best regards,
Juraj Mäsiar

oleh Juraj Mäsiar (Pengembang) pada Feb. 11, 2021 · tautan permanen

Hello again,
Could you check if your other addons are working?
There are some rare cases when extension process crashes and then none of the extensions work.

Best regards,
Juraj Mäsiar