Canon Mark iii not switching on unless card is clean - after recent ML install

[P2K]

I installed ML for the first time on my Canon Mark iii ver 1.2.3 and all was well for a few days of testing - now it wont turn on

1) switches on if SD card only in ( no ML)
2) if the CF card has no ML ie is a clean card it switches on but sometimes have to switch off /remove battery /  with card in and it works
3) records video & pics no problems

I have now installed firmware ver 1.3.3 (means i am stuck now)  this was to see if i can get rid of this fault of not switching on if card is not clean

Ps have only ever used Kingston 32gb 266x cards  on my mark2 with ML and also on the Mark iii

Any one come across this issue ?

[Walter Schulz]

You can downgrade to 1.1.3 or 1.2.3 using EOS Utility v2.x

[dmilligan]

ML only works on a particular specified Canon firmware version. If you change Canon firmware versions, ML will not be able to function. If you are using a recent nightly build, you will actually see an error message to this effect if you try to load ML on the wrong Canon firmware version.

[P2K]

Thanks guys will downgrade after this weekends job and see how it goes - by chance this also happened to one of my freelancers too weekend gone