External Mic not Working with 5D Mk III 1.2.3

[KarneyH]

I used ML with my T2i and so of course I was excited to use it with my new 5D Mk III.  I did a few shoots, a few for clients unfortunately, where I assumed the audio was coming from my Sennheiser wireless lav, but it was actually coming from the internal mic.  On the T2i I have a whole audio menu with AGC on/off, gain, etc. but on the Mk III all I'm getting is Speaker Volume and Beep, test tones.  Something is obviously amiss, probably something simple.  You don't need a module for non-RAW audio, do you?