Work around: Game failed to start (error code 53)

[Hotep]

Right click on "Quake II" in the Library, choose "Properties" , in the "General tab" click on the button "Set Launch Options...", and enter "+set game xatrix" (without the quotes), then start Quake II. To return to the original Quake II, just remove "+set game xatrix" from "Set Launch Options...".