Me again. I removed Gunther's Fear of the Dark and turned Wants & Fears off and used cheats to turn him. He's finally a Vampire, meaning I can play the game again now that Gunther's a vampire, so I'm guessing that was the issue.
So it might be that the fear of dark really blocks the turning process to be completed, since vampires can't have that fear. But it's nice to hear Gunther is now finally living his eternal vampire life! 👍🏼
The modder also wrote that there might be the same problem with mermaids and fear of water 😅
