Why does Canon say that the 5D3 can't be downgraded to 1.1.3?

[mva]

In the Download and Installation Instructions for firmware version 1.2.3 Canon states:

Once the EOS 5D Mark III camera is updated to Version 1.2.0 (or later), it cannot be restored to a previous firmware Version (Version 1.0.7 through 1.1.3).

I realize that many have reported downgrading to 1.1.3 without problems, but I also assume that Canon isn't simply lying or making a mistake. Does anyone have any idea why Canon says this?

[3pointedit]

Perhaps because it goes against their maintenance policy, in other words words Canon supports their own upgrade but won't endorse old software. The way I read it is that Canon cannot restore the old software for you.

[timetraveller]

I don't know why Canon would write that, but I downgraded my 5D3 from 1.2.3 to 1.1.3 without problems, and I'm running ML since then.

Maybe it's their way to try to keep people away from ML, but ML Raw is the best thing that happened for their sales, so it doesn't make sense...

[hjfilmspeed]

I downgraded too!!! worked just fine. Been using for several months!!!

[mva]

Perhaps because it goes against their maintenance policy, in other words words Canon supports their own upgrade but won't endorse old software. The way I read it is that Canon cannot restore the old software for you.

But they don't say you can't go down, e.g., from 1.2.3 to 1.2.1, or from 1.1.3 to 1.1.2. It's the jump from 1.2.0 or higher to 1.1.3 or lower that they say is problematic.

The one thing I've heard is that downgrading to 1.1.3 has caused the AF microadjustment bug to appear for some people who didn't have it previously.

timetravelor and hjfilmspeed: Great to hear that neither of you have noticed any problems. Have you ever checked to see if your AFMA settings switched to -8?

[Marsu42]

so it doesn't make sense...

It does - the reason for Canon stating this would be that in the recent fws, they added extended battery checks to screw 3rd party battery manufacturers, and Canon seems to be very set upon selling more original LP-E6. They even modified the newer chargers so they refuse to charge 3rd party batteries.

[Alex546]

ML is good for the dslr sales but bad for the even more expensive professional market.