I am using the gog version, but because I have tried a different Unity Underworld project, I have extracted the game.gog file. So maybe this is the cause of the issue.
It looks like there was an error saving or loading at one point and all the objects on level 5 are missing. Unfortunately I don't have any more info than that, and the save file is broken beyond repair.
Good to know. Time for a start over I guess :). Yes I have not journaled some conversations anyway. So I guess it is a good time for a restart anyway. I also will replace the Frankenstein Ultima Underworld Installation and put the gog installation there as intended