Exactly, P67II can be operated without film in it. You have run into a problem with the film advance mechanism. It happens right after you fired the shutter and the film advance level won't let you crank again. I have seen some discussion about this somewhere. They said it is dust gets into the film advance mechanism causing something jammed inside. Try to advance the level repeatedly but don't force it. Or tap the advance level with your finger repeatedly. It will work again.