Launch error "No STEAMAPPS_INTERFACE_VERSION009": update Steam
bydread reported GMod failing to launch with "No STEAMAPPS_INTERFACE_VERSION009". robotboy655: the game now uses newer Steam features, so the Steam client must be updated.
GMod Community News Commits, GitHub & Discord. One feed. bydread reported GMod failing to launch with "No STEAMAPPS_INTERFACE_VERSION009". robotboy655: the game now uses newer Steam features, so the Steam client must be updated.