Comment 26 for bug 1850064

Thanks, using "usr.bin.thunderbird" did it. Before, I also did
sudo systemctl stop apparmor.service
sudo update-rc.d -f apparmor remove
sudo systemctl start apparmor.service
sudo update-rc.d apparmor defaults
but I am not sure, if this is related.
Should this be included in the installation process somehow? This may effect other users as well, since I do not think my configuration is very special. However, I do not understand the technical details here. This is the second time, that an automatic update in Ubuntu destroyed my working environment (after the update to 60 that broke all addons, including calendar).