Mod Version:
DynamicSurroundings-1.12.2-3.4.9.11

Forge Version:
forge-1.12.2-14.23.3.2655-universal
If it helps, I'm using SpongeForge 1.12.2-2655-7.1.0-BETA-3064

Link to crash log (if applicable):
https://hastebin.com/ofebirerum.md

Description:
Server crashed on startup. This was the crash report

Smells like Sponge / another mod / plugin. I do not recognize the method:

net.minecraft.world.World.handler$onGetWorldInfo$bbf000(World.java:4680)

Dynamic Surroundings is invoking getWorldInfo() on the world object for the world being loaded, and the underlying code has a fit.