I tried adding the alfheim armor modifier to a laminar chestplate, first it just crashed the client and when i tried to enter the server again it crashed the server. I reproduced the error on a single player world in creative mode.

It lets me add the modifier to a armor np, it's when i put it on the game crashes, this seems true for all armor parts.

[12:03:46] [Server thread/ERROR] [ne.mi.ev.EventBus/EVENTBUS]: Exception caught during firing event: Cannot invoke "java.util.UUID.hashCode()" because "this.f_22193_" is null
Index: 9
Listeners:
0: HIGHEST
1: ASM: class it.mralxart.etheria.leveling.SkillsHandler onArmorEquip(Lnet/minecraftforge/event/entity/living/LivingEquipmentChangeEvent;)V
2: NORMAL
3: ASM: com.bobmowzie.mowziesmobs.server.ServerEventHandler@60fdf0d5 onEquipmentChanged(Lnet/minecraftforge/event/entity/living/LivingEquipmentChangeEvent;)V
4: ASM: class io.redspace.ironsspellbooks.player.ServerPlayerEvents onLivingEquipmentChangeEvent(Lnet/minecraftforge/event/entity/living/LivingEquipmentChangeEvent;)V
5: ASM: class com.hollingsworth.arsnouveau.common.event.PerkEvents equipmentChangedEvent(Lnet/minecraftforge/event/entity/living/LivingEquipmentChangeEvent;)V
6: ASM: class twilightforest.events.MiscEvents armorChanged(Lnet/minecraftforge/event/entity/living/LivingEquipmentChangeEvent;)V
7: ASM: class com.simibubi.create.content.equipment.armor.NetheriteDivingHandler onLivingEquipmentChange(Lnet/minecraftforge/event/entity/living/LivingEquipmentChangeEvent;)V
8: ASM: top.theillusivec4.curios.common.event.CuriosEventHandler@2cd65d9e livingEquipmentChange(Lnet/minecraftforge/event/entity/living/LivingEquipmentChangeEvent;)V
9: net.minecraftforge.eventbus.EventBus$$Lambda$1687/0x000001f4f97a4910@f72192e
java.lang.NullPointerException: Cannot invoke "java.util.UUID.hashCode()" because "this.f_22193_" is null
at TRANSFORMER/[email protected]/net.minecraft.world.entity.ai.attributes.AttributeModifier.hashCode(AttributeModifier.java:95)
at java.base/java.util.HashMap.hash(HashMap.java:338)
at java.base/java.util.HashMap.put(HashMap.java:610)
at java.base/java.util.HashSet.add(HashSet.java:221)
at TRANSFORMER/[email protected]/net.minecraft.world.entity.ai.attributes.AttributeInstance.m_22133_(AttributeInstance.java:76)
at TRANSFORMER/[email protected]/net.minecraft.world.entity.ai.attributes.AttributeInstance.m_22125_(AttributeInstance.java:85)
at TRANSFORMER/[email protected]/tcintegrations.items.modifiers.armor.AlfheimModifier.changeEquipment(AlfheimModifier.java:208)
at TRANSFORMER/[email protected]/tcintegrations.items.modifiers.armor.AlfheimModifier.onEquip(AlfheimModifier.java:127)
at TRANSFORMER/[email protected]/slimeknights.tconstruct.tools.logic.EquipmentChangeWatcher.runModifierHooks(EquipmentChangeWatcher.java:108)
at TRANSFORMER/[email protected]/slimeknights.tconstruct.tools.logic.EquipmentChangeWatcher.onEquipmentChange(EquipmentChangeWatcher.java:68)
at MC-BOOTSTRAP/net.minecraftforge.eventbus/net.minecraftforge.eventbus.EventBus.doCastFilter(EventBus.java:260)
at MC-BOOTSTRAP/net.minecraftforge.eventbus/net.minecraftforge.eventbus.EventBus.lambda$addListener$11(EventBus.java:252)
at MC-BOOTSTRAP/net.minecraftforge.eventbus/net.minecraftforge.eventbus.EventBus.post(EventBus.java:315)
at MC-BOOTSTRAP/net.minecraftforge.eventbus/net.minecraftforge.eventbus.EventBus.post(EventBus.java:296)
at TRANSFORMER/[email protected]/net.minecraft.world.entity.LivingEntity.m_21319_(LivingEntity.java:2410)
at TRANSFORMER/[email protected]/net.minecraft.world.entity.LivingEntity.m_21315_(LivingEntity.java:2381)
at TRANSFORMER/[email protected]/net.minecraft.world.entity.LivingEntity.m_8119_(LivingEntity.java:2287)
at TRANSFORMER/[email protected]/net.minecraft.world.entity.player.Player.m_8119_(Player.java:241)
at TRANSFORMER/[email protected]/net.minecraft.server.level.ServerPlayer.m_9240_(ServerPlayer.java:467)
at TRANSFORMER/[email protected]/net.minecraft.server.network.ServerGamePacketListenerImpl.m_9933_(ServerGamePacketListenerImpl.java:262)
at TRANSFORMER/[email protected]/net.minecraft.network.Connection.m_129483_(Connection.java:263)
at TRANSFORMER/[email protected]/net.minecraft.server.network.ServerConnectionListener.m_9721_(ServerConnectionListener.java:142)
at TRANSFORMER/[email protected]/net.minecraft.server.MinecraftServer.m_5703_(MinecraftServer.java:907)
at TRANSFORMER/[email protected]/net.minecraft.server.MinecraftServer.m_5705_(MinecraftServer.java:814)
at TRANSFORMER/[email protected]/net.minecraft.client.server.IntegratedServer.m_5705_(IntegratedServer.java:89)
at TRANSFORMER/[email protected]/net.minecraft.server.MinecraftServer.m_130011_(MinecraftServer.java:661)
at TRANSFORMER/[email protected]/net.minecraft.server.MinecraftServer.m_206580_(MinecraftServer.java:251)
at java.base/java.lang.Thread.run(Thread.java:840)
[12:03:46] [Render thread/INFO] [minecraft/AdvancementList]: Loaded 301 advancements
[12:03:47] [Server thread/ERROR] [minecraft/MinecraftServer]: Encountered an unexpected exception
net.minecraft.ReportedException: Ticking player
at net.minecraft.server.network.ServerConnectionListener.m_9721_(ServerConnectionListener.java:145) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:classloading}
at net.minecraft.server.MinecraftServer.m_5703_(MinecraftServer.java:907) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:A}
at net.minecraft.server.MinecraftServer.m_5705_(MinecraftServer.java:814) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:A}
at net.minecraft.client.server.IntegratedServer.m_5705_(IntegratedServer.java:89) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,pl:runtimedistcleaner:A,re:classloading,pl:mixin:APP:modernfix-common.mixins.json:perf.thread_priorities.IntegratedServerMixin,pl:mixin:A,pl:runtimedistcleaner:A}
at net.minecraft.server.MinecraftServer.m_130011_(MinecraftServer.java:661) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:A}
at net.minecraft.server.MinecraftServer.m_206580_(MinecraftServer.java:251) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:A}
at java.lang.Thread.run(Thread.java:840) ~[?:?] {re:mixin}
Caused by: java.lang.NullPointerException: Cannot invoke "java.util.UUID.hashCode()" because "this.f_22193_" is null
at net.minecraft.world.entity.ai.attributes.AttributeModifier.hashCode(AttributeModifier.java:95) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,re:classloading}
at java.util.HashMap.hash(HashMap.java:338) ~[?:?] {re:mixin}
at java.util.HashMap.put(HashMap.java:610) ~[?:?] {re:mixin}
at java.util.HashSet.add(HashSet.java:221) ~[?:?] {re:mixin}
at net.minecraft.world.entity.ai.attributes.AttributeInstance.m_22133_(AttributeInstance.java:76) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,re:classloading,pl:mixin:A}
at net.minecraft.world.entity.ai.attributes.AttributeInstance.m_22125_(AttributeInstance.java:85) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,re:classloading,pl:mixin:A}
at tcintegrations.items.modifiers.armor.AlfheimModifier.changeEquipment(AlfheimModifier.java:208) ~[TCIntegrations-1.20.1-2.0.25.8.jar%23494!/:task ':jar' property 'archiveVersion'] {re:classloading}
at tcintegrations.items.modifiers.armor.AlfheimModifier.onEquip(AlfheimModifier.java:127) ~[TCIntegrations-1.20.1-2.0.25.8.jar%23494!/:task ':jar' property 'archiveVersion'] {re:classloading}
at slimeknights.tconstruct.tools.logic.EquipmentChangeWatcher.runModifierHooks(EquipmentChangeWatcher.java:108) ~[TConstruct-1.20.1-3.9.2.37.jar%23498!/:1.20.1-3.9.2.37] {re:classloading}
at slimeknights.tconstruct.tools.logic.EquipmentChangeWatcher.onEquipmentChange(EquipmentChangeWatcher.java:68) ~[TConstruct-1.20.1-3.9.2.37.jar%23498!/:1.20.1-3.9.2.37] {re:classloading}
at net.minecraftforge.eventbus.EventBus.doCastFilter(EventBus.java:260) ~[eventbus-6.0.5.jar%23137!/:?] {}
at net.minecraftforge.eventbus.EventBus.lambda$addListener$11(EventBus.java:252) ~[eventbus-6.0.5.jar%23137!/:?] {}
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:315) ~[eventbus-6.0.5.jar%23137!/:?] {}
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:296) ~[eventbus-6.0.5.jar%23137!/:?] {}
at net.minecraft.world.entity.LivingEntity.m_21319_(LivingEntity.java:2410) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,pl:accesstransformer:B,re:computing_frames,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:APP:forge-badoptimizations.mixins.json:entitydata.MixinLivingEntity,pl:mixin:APP:goety.mixins.json:LivingEntityMixin,pl:mixin:APP:modernfix-forge.mixins.json:perf.forge_cap_retrieval.LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:roll.entity.LivingEntityMixin,pl:mixin:APP:botania_xplat.mixins.json:LivingEntityAccessor,pl:mixin:APP:servercore.common.mixins.json:features.activation_range.inactive_ticks.LivingEntityMixin,pl:mixin:APP:curios.mixins.json:MixinLivingEntity,pl:mixin:APP:attributeslib.mixins.json:LivingEntityMixin,pl:mixin:APP:illageandspillage.mixins.json:LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat117plus.LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat1194plus.LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat1204minus.LivingEntityMixin,pl:mixin:APP:caelus.mixins.json:MixinLivingEntity,pl:mixin:APP:bettercombat.mixins.json:LivingEntityAccessor,pl:mixin:APP:bettercombat.mixins.json:LivingEntityMixin,pl:mixin:APP:ars_nouveau.mixins.json:LivingAccessor,pl:mixin:APP:ars_nouveau.mixins.json:elytra.MixinLivingEntity,pl:mixin:APP:ars_nouveau.mixins.json:perks.PerkLivingEntity,pl:mixin:APP:aether.mixins.json:common.LivingEntityMixin,pl:mixin:APP:aether.mixins.json:common.accessor.LivingEntityAccessor,pl:mixin:APP:lost_aether_content.mixins.json:LivingEntityMixin,pl:mixin:APP:aether_redux.mixins.json:common.entity.LivingEntityMixin,pl:mixin:APP:citadel.mixins.json:LivingEntityMixin,pl:mixin:APP:cataclysm.mixins.json:LivingEntityMixin,pl:mixin:APP:quark.mixins.json:accessor.AccessorLivingEntity,pl:mixin:APP:supplementaries-common.mixins.json:LivingEntityAccessor,pl:mixin:APP:supplementaries-common.mixins.json:LivingEntityMixin,pl:mixin:APP:supplementaries.mixins.json:LivingEntityMixin,pl:mixin:APP:mixins.irons_spellbooks.json:LivingEntityMixin,pl:mixin:APP:create.mixins.json:CustomItemUseEffectsMixin,pl:mixin:APP:create.mixins.json:LavaSwimmingMixin,pl:mixin:APP:create.mixins.json:accessor.LivingEntityAccessor,pl:mixin:APP:pehkui.mixins.json:compat115plus.LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:client.LivingEntityMixin,pl:mixin:A}
at net.minecraft.world.entity.LivingEntity.m_21315_(LivingEntity.java:2381) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,pl:accesstransformer:B,re:computing_frames,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:APP:forge-badoptimizations.mixins.json:entitydata.MixinLivingEntity,pl:mixin:APP:goety.mixins.json:LivingEntityMixin,pl:mixin:APP:modernfix-forge.mixins.json:perf.forge_cap_retrieval.LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:roll.entity.LivingEntityMixin,pl:mixin:APP:botania_xplat.mixins.json:LivingEntityAccessor,pl:mixin:APP:servercore.common.mixins.json:features.activation_range.inactive_ticks.LivingEntityMixin,pl:mixin:APP:curios.mixins.json:MixinLivingEntity,pl:mixin:APP:attributeslib.mixins.json:LivingEntityMixin,pl:mixin:APP:illageandspillage.mixins.json:LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat117plus.LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat1194plus.LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat1204minus.LivingEntityMixin,pl:mixin:APP:caelus.mixins.json:MixinLivingEntity,pl:mixin:APP:bettercombat.mixins.json:LivingEntityAccessor,pl:mixin:APP:bettercombat.mixins.json:LivingEntityMixin,pl:mixin:APP:ars_nouveau.mixins.json:LivingAccessor,pl:mixin:APP:ars_nouveau.mixins.json:elytra.MixinLivingEntity,pl:mixin:APP:ars_nouveau.mixins.json:perks.PerkLivingEntity,pl:mixin:APP:aether.mixins.json:common.LivingEntityMixin,pl:mixin:APP:aether.mixins.json:common.accessor.LivingEntityAccessor,pl:mixin:APP:lost_aether_content.mixins.json:LivingEntityMixin,pl:mixin:APP:aether_redux.mixins.json:common.entity.LivingEntityMixin,pl:mixin:APP:citadel.mixins.json:LivingEntityMixin,pl:mixin:APP:cataclysm.mixins.json:LivingEntityMixin,pl:mixin:APP:quark.mixins.json:accessor.AccessorLivingEntity,pl:mixin:APP:supplementaries-common.mixins.json:LivingEntityAccessor,pl:mixin:APP:supplementaries-common.mixins.json:LivingEntityMixin,pl:mixin:APP:supplementaries.mixins.json:LivingEntityMixin,pl:mixin:APP:mixins.irons_spellbooks.json:LivingEntityMixin,pl:mixin:APP:create.mixins.json:CustomItemUseEffectsMixin,pl:mixin:APP:create.mixins.json:LavaSwimmingMixin,pl:mixin:APP:create.mixins.json:accessor.LivingEntityAccessor,pl:mixin:APP:pehkui.mixins.json:compat115plus.LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:client.LivingEntityMixin,pl:mixin:A}
at net.minecraft.world.entity.LivingEntity.m_8119_(LivingEntity.java:2287) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,pl:accesstransformer:B,re:computing_frames,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:APP:forge-badoptimizations.mixins.json:entitydata.MixinLivingEntity,pl:mixin:APP:goety.mixins.json:LivingEntityMixin,pl:mixin:APP:modernfix-forge.mixins.json:perf.forge_cap_retrieval.LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:roll.entity.LivingEntityMixin,pl:mixin:APP:botania_xplat.mixins.json:LivingEntityAccessor,pl:mixin:APP:servercore.common.mixins.json:features.activation_range.inactive_ticks.LivingEntityMixin,pl:mixin:APP:curios.mixins.json:MixinLivingEntity,pl:mixin:APP:attributeslib.mixins.json:LivingEntityMixin,pl:mixin:APP:illageandspillage.mixins.json:LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat117plus.LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat1194plus.LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat1204minus.LivingEntityMixin,pl:mixin:APP:caelus.mixins.json:MixinLivingEntity,pl:mixin:APP:bettercombat.mixins.json:LivingEntityAccessor,pl:mixin:APP:bettercombat.mixins.json:LivingEntityMixin,pl:mixin:APP:ars_nouveau.mixins.json:LivingAccessor,pl:mixin:APP:ars_nouveau.mixins.json:elytra.MixinLivingEntity,pl:mixin:APP:ars_nouveau.mixins.json:perks.PerkLivingEntity,pl:mixin:APP:aether.mixins.json:common.LivingEntityMixin,pl:mixin:APP:aether.mixins.json:common.accessor.LivingEntityAccessor,pl:mixin:APP:lost_aether_content.mixins.json:LivingEntityMixin,pl:mixin:APP:aether_redux.mixins.json:common.entity.LivingEntityMixin,pl:mixin:APP:citadel.mixins.json:LivingEntityMixin,pl:mixin:APP:cataclysm.mixins.json:LivingEntityMixin,pl:mixin:APP:quark.mixins.json:accessor.AccessorLivingEntity,pl:mixin:APP:supplementaries-common.mixins.json:LivingEntityAccessor,pl:mixin:APP:supplementaries-common.mixins.json:LivingEntityMixin,pl:mixin:APP:supplementaries.mixins.json:LivingEntityMixin,pl:mixin:APP:mixins.irons_spellbooks.json:LivingEntityMixin,pl:mixin:APP:create.mixins.json:CustomItemUseEffectsMixin,pl:mixin:APP:create.mixins.json:LavaSwimmingMixin,pl:mixin:APP:create.mixins.json:accessor.LivingEntityAccessor,pl:mixin:APP:pehkui.mixins.json:compat115plus.LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:client.LivingEntityMixin,pl:mixin:A}
at net.minecraft.world.entity.player.Player.m_8119_(Player.java:241) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:APP:forge-badoptimizations.mixins.json:entitydata.MixinPlayer,pl:mixin:APP:pehkui.mixins.json:reach.PlayerEntityMixin,pl:mixin:APP:playerAnimator-common.mixins.json:PlayerEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:roll.entity.PlayerEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:client.PlayerEntityMixin,pl:mixin:APP:botania_xplat.mixins.json:PlayerMixin,pl:mixin:APP:attributeslib.mixins.json:PlayerMixin,pl:mixin:APP:pehkui.mixins.json:PlayerEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat117plus.PlayerEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat1194plus.PlayerEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat1201minus.EntityVehicleHeightOffsetMixin,pl:mixin:APP:pehkui.mixins.json:compat1204minus.PlayerEntityMixin,pl:mixin:APP:bettercombat.mixins.json:PlayerEntityAccessor,pl:mixin:APP:bettercombat.mixins.json:PlayerEntityMixin,pl:mixin:APP:ars_nouveau.mixins.json:elytra.ElytraPlayerMixin,pl:mixin:APP:aether.mixins.json:common.PlayerMixin,pl:mixin:APP:aether.mixins.json:common.accessor.PlayerAccessor,pl:mixin:APP:comforts.mixins.json:AccessorPlayer,pl:mixin:APP:illager_additions.mixins.json:PlayerMixin,pl:mixin:APP:supplementaries-common.mixins.json:PlayerMixin,pl:mixin:APP:supplementaries.mixins.json:PlayerProjectileMixin,pl:mixin:APP:mixins.irons_spellbooks.json:PlayerMixin,pl:mixin:APP:create.mixins.json:PlayerMixin,pl:mixin:A}
at net.minecraft.server.level.ServerPlayer.m_9240_(ServerPlayer.java:467) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,pl:accesstransformer:B,re:computing_frames,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:APP:betterchunkloading.mixins.json:PlayerChunkDataMixin,pl:mixin:APP:botania_xplat.mixins.json:ServerPlayerMixin,pl:mixin:APP:servercore.common.mixins.json:optimizations.players.ServerPlayerMixin,pl:mixin:APP:pehkui.mixins.json:ServerPlayerEntityMixin,pl:mixin:APP:glitchcore.forge.mixins.json:MixinServerPlayer,pl:mixin:APP:ars_nouveau.mixins.json:camera.ANServerPlayerMixin,pl:mixin:APP:deep_aether.mixins.json:ServerPlayerMixin,pl:mixin:APP:moonlight-common.mixins.json:ServerPlayerMixin,pl:mixin:A}
at net.minecraft.server.network.ServerGamePacketListenerImpl.m_9933_(ServerGamePacketListenerImpl.java:262) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:APP:betterchunkloading.mixins.json:PlayerMovementNoUnloaded,pl:mixin:APP:modernfix-forge.mixins.json:bugfix.forge_vehicle_packets.ServerGamePacketListenerImplMixin,pl:mixin:APP:servercore.common.mixins.json:features.misc.ServerGamePacketListenerImplMixin,pl:mixin:APP:pehkui.mixins.json:ServerPlayNetworkHandlerMixin,pl:mixin:APP:pehkui.mixins.json:compat1204minus.ServerPlayNetworkHandlerMixin,pl:mixin:APP:pehkui.mixins.json:reach.compat1204minus.ServerPlayNetworkHandlerMixin,pl:mixin:APP:pehkui.mixins.json:reach.compat1204minus.compat119plus.ServerPlayNetworkHandlerMixin,pl:mixin:APP:bettercombat.mixins.json:ServerPlayNetworkHandlerMixin,pl:mixin:APP:aether.mixins.json:common.accessor.ServerGamePacketListenerImplAccessor,pl:mixin:APP:cpm.mixins.json:ServerGamePacketListenerImplMixin,pl:mixin:APP:quark.mixins.json:accessor.AccessorServerGamePacketListener,pl:mixin:APP:supplementaries-common.mixins.json:ServerGamePacketListenerMixin,pl:mixin:A}
at net.minecraft.network.Connection.m_129483_(Connection.java:263) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,re:classloading}
at net.minecraft.server.network.ServerConnectionListener.m_9721_(ServerConnectionListener.java:142) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:classloading}
... 6 more

A detailed walkthrough of the error, its code path and all known details is as follows:

-- Head --
Thread: Render thread
Suspected Mods:
Tinkers' Construct (tconstruct), Version: 3.9.2.37
Issue tracker URL: https://github.com/SlimeKnights/TinkersConstruct/issues
at TRANSFORMER/[email protected]/slimeknights.tconstruct.tools.logic.EquipmentChangeWatcher.runModifierHooks(EquipmentChangeWatcher.java:108)
Tinkers' Integrations and Tweaks (tcintegrations), Version: 1.20.1-2.0.25.8
Issue tracker URL: https://github.com/wendall911/TCIntegrations/issues
at TRANSFORMER/[email protected]/tcintegrations.items.modifiers.armor.AlfheimModifier.changeEquipment(AlfheimModifier.java:208)
Stacktrace:
at net.minecraft.world.entity.ai.attributes.AttributeModifier.hashCode(AttributeModifier.java:95) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,re:classloading}
at java.util.HashMap.hash(HashMap.java:338) ~[?:?] {re:mixin}
at java.util.HashMap.put(HashMap.java:610) ~[?:?] {re:mixin}
at java.util.HashSet.add(HashSet.java:221) ~[?:?] {re:mixin}
at net.minecraft.world.entity.ai.attributes.AttributeInstance.m_22133_(AttributeInstance.java:76) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,re:classloading,pl:mixin:A}
at net.minecraft.world.entity.ai.attributes.AttributeInstance.m_22125_(AttributeInstance.java:85) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,re:classloading,pl:mixin:A}
at tcintegrations.items.modifiers.armor.AlfheimModifier.changeEquipment(AlfheimModifier.java:208) ~[TCIntegrations-1.20.1-2.0.25.8.jar%23494!/:task ':jar' property 'archiveVersion'] {re:classloading}
at tcintegrations.items.modifiers.armor.AlfheimModifier.onEquip(AlfheimModifier.java:127) ~[TCIntegrations-1.20.1-2.0.25.8.jar%23494!/:task ':jar' property 'archiveVersion'] {re:classloading}
at slimeknights.tconstruct.tools.logic.EquipmentChangeWatcher.runModifierHooks(EquipmentChangeWatcher.java:108) ~[TConstruct-1.20.1-3.9.2.37.jar%23498!/:1.20.1-3.9.2.37] {re:classloading}
at slimeknights.tconstruct.tools.logic.EquipmentChangeWatcher.onEquipmentChange(EquipmentChangeWatcher.java:68) ~[TConstruct-1.20.1-3.9.2.37.jar%23498!/:1.20.1-3.9.2.37] {re:classloading}
at net.minecraftforge.eventbus.EventBus.doCastFilter(EventBus.java:260) ~[eventbus-6.0.5.jar%23137!/:?] {}
at net.minecraftforge.eventbus.EventBus.lambda$addListener$11(EventBus.java:252) ~[eventbus-6.0.5.jar%23137!/:?] {}
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:315) ~[eventbus-6.0.5.jar%23137!/:?] {}
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:296) ~[eventbus-6.0.5.jar%23137!/:?] {}
at net.minecraft.world.entity.LivingEntity.m_21319_(LivingEntity.java:2410) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,pl:accesstransformer:B,re:computing_frames,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:APP:forge-badoptimizations.mixins.json:entitydata.MixinLivingEntity,pl:mixin:APP:goety.mixins.json:LivingEntityMixin,pl:mixin:APP:modernfix-forge.mixins.json:perf.forge_cap_retrieval.LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:roll.entity.LivingEntityMixin,pl:mixin:APP:botania_xplat.mixins.json:LivingEntityAccessor,pl:mixin:APP:servercore.common.mixins.json:features.activation_range.inactive_ticks.LivingEntityMixin,pl:mixin:APP:curios.mixins.json:MixinLivingEntity,pl:mixin:APP:attributeslib.mixins.json:LivingEntityMixin,pl:mixin:APP:illageandspillage.mixins.json:LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat117plus.LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat1194plus.LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat1204minus.LivingEntityMixin,pl:mixin:APP:caelus.mixins.json:MixinLivingEntity,pl:mixin:APP:bettercombat.mixins.json:LivingEntityAccessor,pl:mixin:APP:bettercombat.mixins.json:LivingEntityMixin,pl:mixin:APP:ars_nouveau.mixins.json:LivingAccessor,pl:mixin:APP:ars_nouveau.mixins.json:elytra.MixinLivingEntity,pl:mixin:APP:ars_nouveau.mixins.json:perks.PerkLivingEntity,pl:mixin:APP:aether.mixins.json:common.LivingEntityMixin,pl:mixin:APP:aether.mixins.json:common.accessor.LivingEntityAccessor,pl:mixin:APP:lost_aether_content.mixins.json:LivingEntityMixin,pl:mixin:APP:aether_redux.mixins.json:common.entity.LivingEntityMixin,pl:mixin:APP:citadel.mixins.json:LivingEntityMixin,pl:mixin:APP:cataclysm.mixins.json:LivingEntityMixin,pl:mixin:APP:quark.mixins.json:accessor.AccessorLivingEntity,pl:mixin:APP:supplementaries-common.mixins.json:LivingEntityAccessor,pl:mixin:APP:supplementaries-common.mixins.json:LivingEntityMixin,pl:mixin:APP:supplementaries.mixins.json:LivingEntityMixin,pl:mixin:APP:mixins.irons_spellbooks.json:LivingEntityMixin,pl:mixin:APP:create.mixins.json:CustomItemUseEffectsMixin,pl:mixin:APP:create.mixins.json:LavaSwimmingMixin,pl:mixin:APP:create.mixins.json:accessor.LivingEntityAccessor,pl:mixin:APP:pehkui.mixins.json:compat115plus.LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:client.LivingEntityMixin,pl:mixin:A}
at net.minecraft.world.entity.LivingEntity.m_21315_(LivingEntity.java:2381) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,pl:accesstransformer:B,re:computing_frames,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:APP:forge-badoptimizations.mixins.json:entitydata.MixinLivingEntity,pl:mixin:APP:goety.mixins.json:LivingEntityMixin,pl:mixin:APP:modernfix-forge.mixins.json:perf.forge_cap_retrieval.LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:roll.entity.LivingEntityMixin,pl:mixin:APP:botania_xplat.mixins.json:LivingEntityAccessor,pl:mixin:APP:servercore.common.mixins.json:features.activation_range.inactive_ticks.LivingEntityMixin,pl:mixin:APP:curios.mixins.json:MixinLivingEntity,pl:mixin:APP:attributeslib.mixins.json:LivingEntityMixin,pl:mixin:APP:illageandspillage.mixins.json:LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat117plus.LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat1194plus.LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat1204minus.LivingEntityMixin,pl:mixin:APP:caelus.mixins.json:MixinLivingEntity,pl:mixin:APP:bettercombat.mixins.json:LivingEntityAccessor,pl:mixin:APP:bettercombat.mixins.json:LivingEntityMixin,pl:mixin:APP:ars_nouveau.mixins.json:LivingAccessor,pl:mixin:APP:ars_nouveau.mixins.json:elytra.MixinLivingEntity,pl:mixin:APP:ars_nouveau.mixins.json:perks.PerkLivingEntity,pl:mixin:APP:aether.mixins.json:common.LivingEntityMixin,pl:mixin:APP:aether.mixins.json:common.accessor.LivingEntityAccessor,pl:mixin:APP:lost_aether_content.mixins.json:LivingEntityMixin,pl:mixin:APP:aether_redux.mixins.json:common.entity.LivingEntityMixin,pl:mixin:APP:citadel.mixins.json:LivingEntityMixin,pl:mixin:APP:cataclysm.mixins.json:LivingEntityMixin,pl:mixin:APP:quark.mixins.json:accessor.AccessorLivingEntity,pl:mixin:APP:supplementaries-common.mixins.json:LivingEntityAccessor,pl:mixin:APP:supplementaries-common.mixins.json:LivingEntityMixin,pl:mixin:APP:supplementaries.mixins.json:LivingEntityMixin,pl:mixin:APP:mixins.irons_spellbooks.json:LivingEntityMixin,pl:mixin:APP:create.mixins.json:CustomItemUseEffectsMixin,pl:mixin:APP:create.mixins.json:LavaSwimmingMixin,pl:mixin:APP:create.mixins.json:accessor.LivingEntityAccessor,pl:mixin:APP:pehkui.mixins.json:compat115plus.LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:client.LivingEntityMixin,pl:mixin:A}
at net.minecraft.world.entity.LivingEntity.m_8119_(LivingEntity.java:2287) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,pl:accesstransformer:B,re:computing_frames,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:APP:forge-badoptimizations.mixins.json:entitydata.MixinLivingEntity,pl:mixin:APP:goety.mixins.json:LivingEntityMixin,pl:mixin:APP:modernfix-forge.mixins.json:perf.forge_cap_retrieval.LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:roll.entity.LivingEntityMixin,pl:mixin:APP:botania_xplat.mixins.json:LivingEntityAccessor,pl:mixin:APP:servercore.common.mixins.json:features.activation_range.inactive_ticks.LivingEntityMixin,pl:mixin:APP:curios.mixins.json:MixinLivingEntity,pl:mixin:APP:attributeslib.mixins.json:LivingEntityMixin,pl:mixin:APP:illageandspillage.mixins.json:LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat117plus.LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat1194plus.LivingEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat1204minus.LivingEntityMixin,pl:mixin:APP:caelus.mixins.json:MixinLivingEntity,pl:mixin:APP:bettercombat.mixins.json:LivingEntityAccessor,pl:mixin:APP:bettercombat.mixins.json:LivingEntityMixin,pl:mixin:APP:ars_nouveau.mixins.json:LivingAccessor,pl:mixin:APP:ars_nouveau.mixins.json:elytra.MixinLivingEntity,pl:mixin:APP:ars_nouveau.mixins.json:perks.PerkLivingEntity,pl:mixin:APP:aether.mixins.json:common.LivingEntityMixin,pl:mixin:APP:aether.mixins.json:common.accessor.LivingEntityAccessor,pl:mixin:APP:lost_aether_content.mixins.json:LivingEntityMixin,pl:mixin:APP:aether_redux.mixins.json:common.entity.LivingEntityMixin,pl:mixin:APP:citadel.mixins.json:LivingEntityMixin,pl:mixin:APP:cataclysm.mixins.json:LivingEntityMixin,pl:mixin:APP:quark.mixins.json:accessor.AccessorLivingEntity,pl:mixin:APP:supplementaries-common.mixins.json:LivingEntityAccessor,pl:mixin:APP:supplementaries-common.mixins.json:LivingEntityMixin,pl:mixin:APP:supplementaries.mixins.json:LivingEntityMixin,pl:mixin:APP:mixins.irons_spellbooks.json:LivingEntityMixin,pl:mixin:APP:create.mixins.json:CustomItemUseEffectsMixin,pl:mixin:APP:create.mixins.json:LavaSwimmingMixin,pl:mixin:APP:create.mixins.json:accessor.LivingEntityAccessor,pl:mixin:APP:pehkui.mixins.json:compat115plus.LivingEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:client.LivingEntityMixin,pl:mixin:A}
at net.minecraft.world.entity.player.Player.m_8119_(Player.java:241) ~[client-1.20.1-20230612.114412-srg.jar%23514!/:?] {re:mixin,pl:accesstransformer:B,re:computing_frames,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:APP:forge-badoptimizations.mixins.json:entitydata.MixinPlayer,pl:mixin:APP:pehkui.mixins.json:reach.PlayerEntityMixin,pl:mixin:APP:playerAnimator-common.mixins.json:PlayerEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:roll.entity.PlayerEntityMixin,pl:mixin:APP:do_a_barrel_roll.mixins.json:client.PlayerEntityMixin,pl:mixin:APP:botania_xplat.mixins.json:PlayerMixin,pl:mixin:APP:attributeslib.mixins.json:PlayerMixin,pl:mixin:APP:pehkui.mixins.json:PlayerEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat117plus.PlayerEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat1194plus.PlayerEntityMixin,pl:mixin:APP:pehkui.mixins.json:compat1201minus.EntityVehicleHeightOffsetMixin,pl:mixin:APP:pehkui.mixins.json:compat1204minus.PlayerEntityMixin,pl:mixin:APP:bettercombat.mixins.json:PlayerEntityAccessor,pl:mixin:APP:bettercombat.mixins.json:PlayerEntityMixin,pl:mixin:APP:ars_nouveau.mixins.json:elytra.ElytraPlayerMixin,pl:mixin:APP:aether.mixins.json:common.PlayerMixin,pl:mixin:APP:aether.mixins.json:common.accessor.PlayerAccessor,pl:mixin:APP:comforts.mixins.json:AccessorPlayer,pl:mixin:APP:illager_additions.mixins.json:PlayerMixin,pl:mixin:APP:supplementaries-common.mixins.json:PlayerMixin,pl:mixin:APP:supplementaries.mixins.json:PlayerProjectileMixin,pl:mixin:APP:mixins.irons_spellbooks.json:PlayerMixin,pl:mixin:APP:create.mixins.json:PlayerMixin,pl:mixin:A}