Gothic 2 NotR bug: no Dragon Hunters in the Valley of Mines

I'm in Chapter 4 in Gothic 2: Night of the Raven and I encountered a bug: there are no Dragon Hunters in the Valley of Mines. This might be connected to another bug which I encountered earlier: after getting the Eye of Innos, I tried to go back to the Valley of Mines, but the game crashed every time I tried to go through the pass. Apparently some other people had similar problems. I was able to fix it by moving the OLDWORLD.SAV file to another folder, going through the pass, and then moving the save file back. I think that when you go through the pass and the chapter changes to 4, new people such as Dragon Hunters are added, but since I restored the save file from chapter 3, they're not there. Is there any way to fix this? I know that I could just insert the people using Marvin codes, but there are lots of them and I don't know where exactly I should insert them, so I could just mess up even worse.