crash:

java.lang.NullPointerException: Exception ticking world
    at net.minecraft.world.GameRules.func_223586_b(SourceFile:185) ~[?:?] {re:mixin,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:APP:betterweather.mixins.json:access.GameRulesAccess,pl:mixin:APP:architectury.mixins.json:GameRulesAccessor,pl:mixin:A}
    at dev.necro.coyotelib.common.game_rules.ArachnophobiaGameRule.entitySpawn(ArachnophobiaGameRule.java:21) ~[coyotelib:1.3.4] {re:classloading}
    at net.minecraftforge.eventbus.ASMEventHandler_700_ArachnophobiaGameRule_entitySpawn_EntityJoinWorldEvent.invoke(.dynamic) ~[?:?] {}
    at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:85) ~[eventbus-4.0.0.jar:?] {}
    at net.minecraftforge.eventbus.EventBus.post(EventBus.java:302) ~[eventbus-4.0.0.jar:?] {}
    at net.minecraftforge.eventbus.EventBus.post(EventBus.java:283) ~[eventbus-4.0.0.jar:?] {}
    at net.minecraft.world.server.ServerWorld.func_72838_d(ServerWorld.java:814) ~[?:?] {re:mixin,pl:runtimedistcleaner:A,re:classloading,pl:mixin:APP:performant.mixins.json:world.ServerWorldBlockUpdateMixin,pl:mixin:APP:betterweather.mixins.json:access.ServerWorldAccess,pl:mixin:APP:betterweather.mixins.json:server.world.MixinServerWorld,pl:mixin:APP:enhancedcelestials.mixins.json:MixinServerWorld,pl:mixin:APP:performant.mixins.json:world.ServerWorldMixin,pl:mixin:A,pl:runtimedistcleaner:A}
    at net.minecraft.world.server.ServerWorld.func_217376_c(ServerWorld.java:755) ~[?:?] {re:mixin,pl:runtimedistcleaner:A,re:classloading,pl:mixin:APP:performant.mixins.json:world.ServerWorldBlockUpdateMixin,pl:mixin:APP:betterweather.mixins.json:access.ServerWorldAccess,pl:mixin:APP:betterweather.mixins.json:server.world.MixinServerWorld,pl:mixin:APP:enhancedcelestials.mixins.json:MixinServerWorld,pl:mixin:APP:performant.mixins.json:world.ServerWorldMixin,pl:mixin:A,pl:runtimedistcleaner:A}
    at java.util.stream.Streams$StreamBuilderImpl.forEachRemaining(Streams.java:419) ~[?:1.8.0_352] {}
    at java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:742) ~[?:1.8.0_352] {}
    at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:647) ~[?:1.8.0_352] {}
    at net.minecraft.world.IServerWorld.func_242417_l(SourceFile:11) ~[?:?] {re:mixin,re:computing_frames,re:classloading}
    at net.minecraft.world.spawner.WorldEntitySpawner.func_234966_a_(WorldEntitySpawner.java:178) ~[?:?] {re:mixin,re:classloading,pl:mixin:APP:enhancedcelestials.mixins.json:MixinWorldEntitySpawner,pl:mixin:APP:enhancedcelestials.mixins.json:access.WorldEntitySpawnerAccess,pl:mixin:A}
    at net.minecraft.world.spawner.WorldEntitySpawner.func_234967_a_(WorldEntitySpawner.java:124) ~[?:?] {re:mixin,re:classloading,pl:mixin:APP:enhancedcelestials.mixins.json:MixinWorldEntitySpawner,pl:mixin:APP:enhancedcelestials.mixins.json:access.WorldEntitySpawnerAccess,pl:mixin:A}
    at net.minecraft.world.spawner.WorldEntitySpawner.func_234979_a_(WorldEntitySpawner.java:110) ~[?:?] {re:mixin,re:classloading,pl:mixin:APP:enhancedcelestials.mixins.json:MixinWorldEntitySpawner,pl:mixin:APP:enhancedcelestials.mixins.json:access.WorldEntitySpawnerAccess,pl:mixin:A}
    at net.minecraft.world.server.ServerChunkProvider.func_217220_m(ServerChunkProvider.java:676) ~[?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:mixin:APP:performant.mixins.json:world.chunk.ServerChunkProviderMixin,pl:mixin:APP:betterweather.mixins.json:access.ServerChunkProviderAccess,pl:mixin:APP:enhancedcelestials.mixins.json:MixinServerChunkProvider,pl:mixin:APP:performant.mixins.json:world.chunk.ServerChunkProviderThreadsMixin,pl:mixin:A,pl:runtimedistcleaner:A}
    at net.minecraft.world.server.ServerChunkProvider.func_217207_a(ServerChunkProvider.java:326) ~[?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:mixin:APP:performant.mixins.json:world.chunk.ServerChunkProviderMixin,pl:mixin:APP:betterweather.mixins.json:access.ServerChunkProviderAccess,pl:mixin:APP:enhancedcelestials.mixins.json:MixinServerChunkProvider,pl:mixin:APP:performant.mixins.json:world.chunk.ServerChunkProviderThreadsMixin,pl:mixin:A,pl:runtimedistcleaner:A}
    at net.minecraft.world.server.ServerWorld.func_72835_b(ServerWorld.java:334) ~[?:?] {re:mixin,pl:runtimedistcleaner:A,re:classloading,pl:mixin:APP:performant.mixins.json:world.ServerWorldBlockUpdateMixin,pl:mixin:APP:betterweather.mixins.json:access.ServerWorldAccess,pl:mixin:APP:betterweather.mixins.json:server.world.MixinServerWorld,pl:mixin:APP:enhancedcelestials.mixins.json:MixinServerWorld,pl:mixin:APP:performant.mixins.json:world.ServerWorldMixin,pl:mixin:A,pl:runtimedistcleaner:A}
    at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:851) ~[?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
    at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:291) ~[?:?] {re:classloading,pl:accesstransformer:B}
    at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:787) ~[?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
    at net.minecraft.server.MinecraftServer.func_240802_v_(MinecraftServer.java:642) ~[?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
    at net.minecraft.server.MinecraftServer.func_240783_a_(MinecraftServer.java:232) ~[?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
    at java.lang.Thread.run(Thread.java:750) [?:1.8.0_352] {}

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Please update to a modern version of Minecraft to receive support.

Currently supported versions are 1.19.3 (Latest), 1.19.2, and 1.18.2 (LTS).