On 2/15/2026 12:42 AM, Shawn K. Quinn wrote: > After a reboot I was finally able to restart Thunderbird. I took the > drastic step of `rm /etc/apparmor.d/usr.bin.thunderbird` (I have backups > if I need to restore it) as aa-complain said there was a syntax error in > that file. (Or, most likely, it will be reinstalled with a later > version, hopefully with this syntax error fixed.) >
That is drastic. I did not see any message from aa-complain saying there was a syntax error in /etc/apparmor.d/usr.bin.thunderbird but the history of my installation is Ubuntu-free. I suspect the syntax error is an artifact of that old Ubuntu installation you upgraded from, so I wouldn't bring back that file but try to restore the correct, default, Debian one. I am not sure what the best way to do that is, though. Hopefully Carsten will weigh in with some advice for you. I would also check to see if /etc/apparmor.d/disable/usr.bin.thunderbird exists. If it does not, I would recommend creating it because if you do restore the correct, Debian version of /etc/apparmor.d/usr.bin.thunderbird either manually or automatically in some future update, your Thunderbird will likely be broken again without /etc/apparmor.d/disable/usr.bin.thunderbird which by default on Debian, AFAICT, should be a symlink to /etc/apparmor.d/usr.bin.thunderbird which can be created by something like: $ sudo mkdir -p /etc/apparmor.d/disable $ sudo ln -s /etc/apparmor.d/usr.bin.thunderbird /etc/apparmor.d/disable/usr.bin.thunderbird The reason my Thunderbird broke was that the symlink in /etc/apparmor.d/disable was missing, and I have verified that adding the symlink was an alternate way to workaround this bug on my box, instead of running aa-complain on /etc/apparmor.d/usr.bin.thunderbird. I think that is the better way to workaround the bug if you desire your installation to, as closely as possible, restore the default Debian installation of Thunderbird, but I could be wrong and I suggest you should prefer any advice Carsten might have for you on how best to fix your system since Carsten is the person who has been maintaining Thunderbird on Debian for a long time, AFAICT. Cheers.
