Well, I think I did it now. I forgot to pick up the Blue Key (the last of four mini-bosses prior to the Hell God) so I went back to get it. Had to fight that final one again, picked up the (missing) key, and tried to head back to the previous level(s). But now It seems I am stuck for good. Even though the doors are open I can't get through. So I think maybe I have to fight may way around again in sequence (to trigger the doors to get out), but this does no good because I can't pick up already picked up keys EVEN THOUGH the key is visible on the ground.

Anyone else see this and resolve the issue?
<edit>
It's even worse than I thought. I happened to have a save while still doing the four mini-bosses. I completed the level and accrued all four keys. But I am still stuck in the level and can't leave it. Same as before: the door is open and the map shows it as being connected but the game engine thinks I can't walk through.

Anyone else seen this and/or resolved it?
</edit>

<edit 2>
Starting from an even earlier save I get to the same place with the same results. This is a GAME STOPPING BUG for me.
</edit 2>.

<edit 3>
Even installing original retail + patches on a generously loaned old PC and using my saves results in the same conundrum. Game breaking bug. Wonder how this ever worked when I played this "back in the day".
*SIGH*
</edit 3>

<edit the last>
Could the saves contain map layouts? I always thought the saves were just character stats and location within a map but not complete maps. Mmm.

Anyway.

Seeing that I'm solidly stuck behind an invisible wall where the door is which leads to the next part of the level/map/dungeon, and so can't continue, if anyone has a savegame from just before the Hell God or just after the 4 Draxx-like mini bosses where you get the four keys required for said next level/map/dungeon... If you will share it... Well, I'll just have to accept that and continue on with someone else's character "builds". ;)
</edit the last>

*SIGH* I lied. This is the last edit. I actually got through the "invisible wall". The issue this particular door has is there is a VERY restrictive path to follow. This isn't apparent from the picture presented. Reminiscent of some old style point&click adventures, I had to stand on JUST the right location on one side of the door and click JUST the right tiny area on the other side. VIOLA! Maya and crew walk through.