I can confirm that when using the unity session, the reminder window can be minimized, whereas in the stock (GNOME) Ubuntu session, it cannot, and it remains on top of the main thunderbird window.
** Changed in: thunderbird (Ubuntu) Status: New => Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1869470 Title: Can't minimize Thunderbird Lightning reminder window To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/thunderbird/+bug/1869470/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs