I heard that there a certain glitch in U7 with the MC when flying over a certain spot , can anyone tell me if this is true and what the glitch so I can avoid it.?

Thank you in advance.

True. There's a spot in the dungeons on the Isle of the Avatar where a door is triggered by proximity, without taking vertical location into account. This means flying over the trigger will also trigger it to shut the door, blocking further progress in the game. Avoid flying over mountains on the Isle and you should be fine.

It's been a long while, so maybe I am wrong, but there's also the infamous room where, if you're in it/flying over it, Lord British calls you a cheater and kills you on the spot.
Other 'eggs'/triggers might be activated as well when you're flying over them, although most won't lead to a game stopper.

So yeah, if you use the Magic Carpet, definitely avoid flying over mountains.

Just tried it: You can still save since you'll wake up at the shelter as usual anyway. But if you encounter this room the world will be in 'armageddon'-mode, e.g. everyone except for you and LB will be dead.

Ah so avoid flying over the isle of the avatar , thank you very much. damn thank you as well :) . fly over land, got it

Yes, you can save, but you don't have to save, and because it's obvious that something is wrong (unlike the case of flying of the Isle of the Avatar), you can choose not to save.

Also, I note that Batlin will be there (and will say what he normally does post-Armageddon), as will the ferryman who takes you to ruined (again) Skara Brae. (How many times has this town been destroyed in classic CRPGs? There's this game, one of the other Ultimas, and Bard's Tale 3, all which had a town with that name in ruins.)

As I said, however, I strongly suggest talking to Lord British a few times after being accused of cheating. He does not say the same thing he says post-Armageddon.

It was a joke on one of the programmers. He created a teleporter to the super cheaty debug room, and when the rest of the team found it, they changed his teleporter to take him to this room instead where Lord British chastises him.