1D mark 2 error 1 messege

Hey everyone,

So I just bought a converted rokkor-X 50mm F/1.2. The lens works beautifully on my 7D,

On my 1D mark 2, I get an error 1 message, the mirror reflexes up and the shutter stays closed. the 1D refuses to take a picture with this lens attached... It will fire with no lens attached however.

So far, I have tried taping the contacts thinking hey maybe it will work. No such luck.

Does anyone have any ideas?

thanks guys