I found a cause. I use this GNOME Shell extension. https://extensions.gnome.org//extension/4691/pip-on-top/ This problem is a bug from this extension. I will report this bug to extension's developer.
Anyway, This Issue is not Ubuntu's bug. Sorry and Thank you. -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/1982611 Title: gnome-shell crashed in meta_window_unmanage: assertion failed: (g_list_find (workspace->windows, window) == NULL) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1982611/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs