https://bugs.winehq.org/show_bug.cgi?id=56429
--- Comment #5 from random-nick@mail.com --- I did some testing with taskmgr on various desktop environments, under the assumption that this varies according to setup, and it seems that this might be a bug related to the systray. On DEs such as GNOME and Openbox where there is no systray (and so the wine systray is used) there are no X errors and it seems to work correctly. On most DEs I tested which have a systray (LXDE, LXQt, MATE, XFCE, Cinnamon on X11) the reproduction steps in Comment 1 work as is written. The only DE I tested with a systray where the they don't is KDE, but the first X error still shows up and it seems to break the systray for wine applications (e.g. if you have 2 taskmgrs and so 2 systray icons, when you trigger the bug by closing one taskmgr, both tray icons will disappear)