Using a 5D Mark ii here. Working OK for a long time. ML started acting a little flaky a couple of weeks ago. Today, when I tried to reformat the card in the camera, it froze on format saying "Busy...". The only thing that worked was to remove the battery. On turning the camera, on ML is gone and the camera works as expected from the factory, records images and videos just fine.
What would be the proper way to start over and get ML installed?
I could not figure out how to post a question any other place so I did it here.