[12:00:52] [Server thread/INFO] [roguelike]: Trying to spawn dungeon at chunkX 0 and chunkZ 0...

I think it's a configuration issue. I delete roguelike_dungeons and enter the world. And then I add settings.
/roguelike settings reload

[12:17:30] [Server thread/INFO] [com.github.fnar.roguelike.command.commands.BaseRoguelikeCommand]: java.lang.RuntimeException: Error in: E:\Minecraft\ALNL.minecraft\versions\csmod\config\roguelike_dungeons\settings\fnar\vanilla\dungeon\villager_house\dungeon_villager_house.json: An unknown error occurred while parsing json: class java.lang.IllegalArgumentException No enum constant com.github.fnar.minecraft.world.BiomeTag.MOUNTAINS
[12:17:30] [Client thread/INFO] [net.minecraft.client.gui.GuiNewChat]: [CHAT] Failure: Error in: E:\Minecraft\ALNL.minecraft\versions\csmod\config\roguelike_dungeons\settings\fnar\vanilla\dungeon\villager_house\dungeon_villager_house.json: An unknown error occurred while parsing json: class java.lang.IllegalArgumentException No enum constant com.github.fnar.minecraft.world.BiomeTag.MOUNTAINS (3)

Ah, the MOUNTAINS issue.
Rename it to MOUNTAIN and it should work.

@KameiB I really don't deserve you 😭 Thank you for helping @al-wei with their issue.

I'm hoping that this is resolved, so I am marking the issue as closed. Please feel free to re-open it again if you believe it is a bug with the mod. If you feel that it is a configuration issue, we'd be happy to help you in the discord server:
https://discord.gg/PhBwykGH

@KameiB I really don't deserve you 😭 Thank you for helping @al-wei with their issue.

I'm hoping that this is resolved, so I am marking the issue as closed. Please feel free to re-open it again if you believe it is a bug with the mod. If you feel that it is a configuration issue, we'd be happy to help you in the discord server: https://discord.gg/PhBwykGH

@KameiB @fnar Thanks, actually I probably know it's not a roguelike problem, I'm more interested in the config problem.
My modpack reached 450+ mods, and I might be suspicious of any mod.