I too have this problem. It seems that if you go into your .thunderbird directory and delete the file addonStartup.json.lz4, thunderbird is able to start. Restarting tb usually causes the error to appearagain, but re- deleting this file allows it to start again.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1901829 Title: thunderbird fails to open, xml parse error To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/thunderbird/+bug/1901829/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
