Can't get to portal room in ARC Complex | Bug

So I'm currently playing ARC Complex and got myself every secret and now want to get back to the marauder room and into the portal. The only problem is, the elevator, that you used in the final cutscene of the level, is not usable as an normal elevator. Also there is no fast travel available to the room.
If there is a solution, glitch or flyhack, you could recommend, I would be gratefull

The room with the elevator.

Here you can see, that I can't get into the elevator.