hi i was having this issue with my 60d few days ago. hope you can help. i was shooting weddings then it came out err 70 then i open the battery tray then i put it back it went fine. but kinda worries me for future wedding jobs if this issue keep occuring.
this is from the log ASSERT: FALSE at SoundDevice\SoundDevice_CODEC.c:1048, task ASIF lv:0 mode:20
Magic Lantern version : Nightly.2016Aug24.60D111 Mercurial changeset : 96ca71e19bf1 (unified) tip Built on 2016-08-23 22:15:33 UTC by email@example.com. Free Memory : 380K + 1708K