I'm also affected by this bug when using Thunderbird but I've found a workaround: Unpin Thunderbird (right click on the icon and "Remove from Favorites"). After that you can still start Thunderbird manually, it won't trigger this bug any more when it is just a normal application (and not a "favorite" application with a fixed place in the Dock).
-- 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