So about a Month ago I got the Canon 5D Mark II and it came with the 2.0.4 update ok so back to the error..
Last week I got the Canon Battery Grip BG-E6 and I also got on more Battery so I can have 2 whats a battery grip without 2 batteries right.
So when I put my battery grip on my camera and when i turned it a black screen goes on and tells me this Cannot communicate with battery and gives me the option to either cancel or continue and when i selected continue noticed that the battery level was shown empty. So I take out the Canon Batteries and use 6AA Batteries and that works just fine.
Can some one tell me how to fix this?