6D, a choosy missy
I bought a 60D with an extra 3rdparty battery that did seem to work well with my 7D. I also had a Big-S m42 adapter which worked well with both cams.
After getting the 6D I sold all my apsc/ef-s stuff. I kept the 2 items I’ve mentioned above. I was thinking they will do well with the 6D. But the 6D won’t communicate with the battery and will flash some lens error messages with the Big-S adapter. The 6D charger also won’t load up on the 3rdparty battery.
I was about to get rid of these items but then I bought a used 5D mk2. Well, they work just fine on the 5Dmk2.
I guess, my young 6D is one picky miss.