Hi, Since a few weeks, I have a problem with Thunderbird (current version 78.12) and Ubuntu Dock / Dash to Dock in Ubuntu 21.10 : When I write a new message and send it, after the message window has closed, its red dot remains near Thunderbird button on the Ubuntu dock - there are 2 dots: the one of main TB window (receipt box) and a second one as if there was another window still opened. But if I switch to another application - Firefox, Gedit, Nautilus, no matter… - and then with the mouse (left button) click on Thunderbird icon, desktop freezes completely, I have to manually close the computer and restart it. All is frozen, mouse nor Alt-Tab don't work, but if for example Radiotray was active, I can still hear the audio program live. If I just roll the middle button on the mouse to switch on Thunderbird and not click, it doesn't freeze. But to be back on TB main window, I must before minimize all other applications, then run somewhere in TB interface (not on Dash button), or roll is useless and doesn't show Thunderbird. If I open a window for a new message, don't send it and just close it, only one red dot stays and no freeze, even with a left button click. I also report the bug upstream. Crash logs : Jul 2 18:41:14 valeryan24-desktop gnome-shell[2311]: Object St.Bin (0x55c216acf060), has been already deallocated — impossible to set any property on it. This might be caused by the object having been destroyed from C code using something such as destroy(), dispose(), or remove() vfuncs. Jul 2 18:41:14 valeryan24-desktop gnome-shell[2311]: == Stack trace for context 0x55c213c2c1d0 == Jul 2 18:41:14 valeryan24-desktop gnome-shell[2311]: #0 7ffe8ca71020 b /