Server keeps crashing

I installed about 14 mods and the server worked super well until today. i woke up, started the server, and for some reason it crashed. i already removed one of my mods, immersive portals (which seems to be the most buggy) but it still crashed. the thing is, last night it had absolutely no problems. here is the log in case if anyone understands. Thanks! help much appreciated

Immersive portals (removed)

biomes o plenty

conjurer

backpacked

yungs better mineshaft

yungs better caves

dungeons plus

valhelsia structure

repurposed structures

mining helmet

leap

double slabs

spiders 2.0

structure gel api

I removed and installed it again. nothing changed