Plz check the crash log file. My 5dmk3 abruptly stopped with error message 70.
I'm familiar with err 70 or err 80 in 5dmk3. It's a critical error in canon firmware 1.1.3. In my humble opinion, ML should be based on the recent canon firmware like 1.2.1. or 1.2.3. Canon's 1.2.1 firmware solved TONS of errors and bugs.
Pz Tell me what I can do with the error.