How it happened: I made a timelapse with magic lantern, taking hundreds of pictures with an interval of a few seconds My battery was empty before the end of the timelapse
Bug: after recharging my battery and taking a normal picture (even without magic lantern), the autofocus mode does not work anymore in "normal" mode. Fortunately, the autofocus still works in "live view" mode.
I expect I'll fix the issue by restoring the original firmware.
How to avoid: My assumption is that the bug happened because the battery got empty in the middle of a picture or so. Therefore, it would be great that the picture interval would stop automatically if battery is let's say below 5%.