Hi. It seems some of the extensions I use aren't ready for the update to Thunderbird 140. Unfortunately, Thunderbird didn't warn me about this before updating. I managed to update most of them, but it would be great if TB could check compatibility before the update. I assume this should be doable, since version compatibility is listed in the add-ons database and is already checked after the update.
Otherwise, good work on the update – it looks nice 🙂