Im on level 16 (Catacombs) and I'm unable to progress because of the door to Keldus Magnor's Tomb doesn't move. All the walkthrough I've read said that the door should slide back into the wall but nothing happens. The last Hero key I need is beyond that door ...

Does anyone have an idea on what I might be missing ?

Thanks

Better late than never I guess.

Thunderscape is a buggy game that suffers from memory corruption. The more levels you visit in a single session, the more likely these bugs will occur.

I had a similar issue in the Catacombs on my last play-through. What you have to do is leave the Catacombs (back to the caves). Exit the game and navigate into your save file directory and delete the catacombs Map file. This will reset the map and allow you to proceed (though all progress in the Catacombs level will be reset). At least you get to keep your items and xp!