Just for the records how I as an Canon 6D V1.1.6 owner was able to enable the "Junkie Menu" and fixed the dual-iso error message:
Enable Junkie Menu
I added the following code line at the very end of the file /magic-lantern/platform/6D.116/features.h
#define FEATURE_JUNKIE_MENU
Fix the dual-iso error "ISOless PH err(3)"
I modified the following code lines in /magic-lantern/modules/dual_iso/dual_iso.c
Original:
FRAME_CMOS_ISO_START = 0x40452196; // CMOS register 0003 - for LiveView, ISO 100 (check in movie mode, not photo!)
...
PHOTO_CMOS_ISO_START = 0x40450E08; // CMOS register 0003 - for photo mode, ISO 100
Fixed:
FRAME_CMOS_ISO_START = 0x404e6196; // CMOS register 0003 - for LiveView, ISO 100 (check in movie mode, not photo!)
...
PHOTO_CMOS_ISO_START = 0x404e4e08; // CMOS register 0003 - for photo mode, ISO 100
Both things I found out by digging in the source code of different branches and searching through various forum threads. As always, everything you are doing, you are doing on your own risk. Don't blame me!