Stuck on Legacy of Suffering

Hey,

me and my brother are stuck on the seemingly final map of LOS. We fought the translucent boss in the center of the map. Now he's despawned, the music stopped, some lights went on but nothing else happened. We still cannot enter the red door, it won't even display the "access forbidden bla bla" popup window anymore.

Any idea? Is the scripting bugged maybe?

Step onto the one of the teleporter pads where the shadow boss is lying.

The shadow boss has despawned and stepping onto the teleporter pad in our savegame doesn't do anything.

I just started a singleplayer game and cheated to that spot and there the boss did not despawn and stepping onto the platform triggers the ending credits, followed by a hell level of some sort.

So I guess some scripting is buggy in coop... :(

If I remember right, there's nothing but the endgame after the shadow boss anyway...

As I said, there is a hell level after that. But I'm not sure if that's supposed to be SP only. We +map 'ed in there and at least one teleporter was useless in coop, due to the "repeatable" flag not set... We ended up with everyone playing that level for himself.