For some reason X.org will not be disabling the behaviour that triggers the problem by default. Even after you have the new X.org X server release you have to do the following to prevent this problem: > Support for such clients may also be disabled for the Xorg server by > providing a file in `/etc/X11/xorg.conf.d/` containing the contents: > > ``` > Section "ServerFlags" > Option "AllowByteSwappedClients" "False" > EndSection > ``` I’ll add that to my standard desktop system config.