Thunderbird can take many seconds to start and close, so sometimes it does really still have some windows half-prepared in memory but not visible. That strange state might be a contributing factor.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1933996 Title: Alt-tab stops switching windows [JS ERROR: TypeError: window is null _createWindowClone@resource:///org/gnome/shell/ui/altTab.js:29:27] To manage notifications about this bug go to: https://bugs.launchpad.net/gnome-shell/+bug/1933996/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
