Mamiya 645 Troubles

I took out my Mamiya 1000S to give it some exercise, loaded a 120 insert, put it into the camera and tried to wind up the leader for the first frame.
The knob didn't move. I tried snapping a picture and the shutter worked , but still couldn't advance the film. Took the film out, put it on another 120 insert, and the same thing happened. I even tried a 220 insert and nothing. Without any film in the camera and the insert in , I can snap the shutter and wind up the handle fine.
I'm assuming the camera has a problem; Now is there something I can do to remedy this problem or am I going to have to send it for service

Thanks
rob

Look at the multi exposure knob to be in the correct position.
It is in the manual.
If you don't have a manual and can't find it online, PM me and I will send you a copy.
Also notice that you have to advance your film to the starting point (arrows) on the film insert before
placing it in the body.

Best regards,
LCEL.

That was it! How on earth did that switch get pulled over I don't know (must be gremlins)

Thank you very much
rob