Is it a mod compatibility issue?

No

If it's a mod compatibility issue, please provide the link(s) to the incompatible mod(s)

No response

Minecraft version

1.20.1

Describe the issue

This is a note: For other who suffers the same issue as mine. just USE forge 1.20.1 47.4.1.

Other than that: The condition is tested only with "Immersive Portals (for Forge)" is used which result in the same crashing when press on the "Create new world". I discover about the main problem when one of my old "forge test" which is made long ago worked fine. Hope this help!