Hi, meanwhile I found out that thunderbird's Debian package ships an apparmor profile (which prevents several things, e.g. reading ~/.local/share/recently-used.xbel):
$ dpkg -s thunderbird | grep apparmor.d /etc/apparmor.d/usr.bin.thunderbird 84c1c996844c0c4350c30fd890f85e6c According to /usr/share/doc/thunderbird/README.apparmor, the mentioned profile is supposed to be disabled by default. Well, I don't know why, but in my case, the profile has been effective, instead. Then I tried two things. First, I purged apparmor. Everything works. Second, I reinstalled apparmor. Everything (still) works. Seems that reinstalling apparmor initializes thunderbird's apparmor-configuration (and does is right, this time). So, if anyone else has the same issues, try to do the following. $ sudo apt purge apparmor $ sudo apt install apparmor I hope that helps. (If not, I'm quite sure that getting rid of thunderbird's apparmor-profile in any other way (e.g. removing), should also be promising...) Regards, Gerhard
