a1ex is the key to sign .fir files changed?
If yes, is there a chance to edit the fw version in the old 1.2.3 and show it to the camera as 1.3.3 or 1.3.0?
From what some Italian users explained on the Facebook user group, it seems that canon has blocked the EOS Utility downgrade method. They tried with a few new and old versions of the software, but nothing done. Software issue solved