The game crashes if you press the Config button in the Mods menu on Neoforge 21.0.134-beta, so do many other mods (neoforged/NeoForge#1357, blackd/libIPN#21).

Here's the crash log: https://mclo.gs/fDFyHYm

You have to update to Cloth Config 15.0.128.

You have to update to Cloth Config 15.0.128.

I have the same problem ever since I switched from forge to neoforge and any time I try to use the config button the game crashes no matter how many mods there are 1 or 70. For example I have the 15.0.128 version of Cloth Config but config still crashes the game. I also can't run the game with the configured mod which could be the problem but the game gives an uncaught parallel processing error.

Make sure you are on the latest NeoForge AND Cloth Config.