Quoting the previous fix (found here: https://mods.vintagestory.at/show/mod/7182)

Not my work, all credit to original author. What does this include? This mod is basically a fix to the original mod to prevent the crash to desktop exception from occuring when selecting the traits page. I also added the Tailor into the class tree as it was missing in the original mod. Hopefully sometime soon I'll add a new class called the Alchemist which would work similar to the Minecraft witch, able to do healing and damage potions for allies and enemies. Any ideas are welcome as I have an interest in maintaining this fork until the original is updated. The glorious original mod: https://mods.vintagestory.at/show/mod/449

All I did was re-add the claustrophobic trait to traits.json to stop it from crashing on the class selection menu.