Project Paragon Crash Minecraft modpack
Project Paragon Crash Minecraft modpack
Optifine isn't needed since it's known to cause issues with the modpack.
Based on the stack trace, nothing seems particularly clear or notable.
You might want to remove a few mods together and see if it resolves the problem. The stack trace suggests it's loading mixins for enhancedcelestials and elementalcraft just before the crash. You could skip those temporarily. Check the console output around line 770 in net.minecraft.server.MinecraftServer.java to confirm which mod is involved.