Fun find this weekend when disks failed on one of the gateways after power cut. Boot sequence suggested to run disk verification in maintenance mode, but when we attempted to log in, our access was denied due to wrong password.
We knew two things for sure: we must use expert password and we knew it was correct.
So had no choice but to rebuild the box.
But later today I attempted to replicate the issue in our lab and what we found was that entering maintenance mode will fail if your expert password is longer than 26 characters! We used 32... no special characters, just numbers and letters.
@_Val_ - do you think you are able to find responsible at R&D? I won't have time to chase TAC case I'm afraid. But it's fairly easy to replicate. We are on R80.40 T156.