i get permakicked when theres any item in my offhand.
i tried finding out the cause of this on my own. but no matter what i tried the only way was to remove epic fight mod.

server hoster:aternos
forge version : 36.2.8
mods :
AI-Improvements-1.16.2-0.3.0.jar
Chunk Pregenerator-V1.16-3.1.1.jar
cloth-config-4.11.26-forge.jar
dungeons_gear-1.16.5-3.0.17.jar
DungeonsArise-1.16.5-2.1.47-release.jar
EpicFightMod-1.16.5-5.1.5.jar
ferritecore-2.1.0-forge.jar
jei-1.16.5-7.7.1.129.jar
MedievalCraft-1.16.5-1.16.1.jar
mostructures-forge-1.2.0-1.16.5.jar
performant-1.16.2-5-3.72m.jar
randompatches-2.4.4-forge.jar
repurposed_structures_forge-3.3.4+1.16.5.jar
SpartanWeaponry-1.16.4-2.1.0-beta-4.jar
stoneholm-1.2.2.jar
vanilladeathchest-1.16.3-1.11.0.8.jar

logs when error happens.

1473 | [28Oct2021 15:59:10.585] [Server thread/ERROR] [net.minecraftforge.eventbus.EventBus/EVENTBUS]: Exception caught during firing event: net.minecraft.entity.ai.attributes.ModifiableAttributeInstance.func_142049_d()V
1474 | Index: 4
1475 | Listeners:
1476 | 0: NORMAL
1477 | 1: ASM: class com.oblivioussp.spartanweaponry.event.CommonEventHandler onEquipmentChange(Lnet/minecraftforge/event/entity/living/LivingEquipmentChangeEvent;)V
1478 | 2: ASM: class com.infamous.dungeons_gear.items.melee.MeleeEvents dualWield(Lnet/minecraftforge/event/entity/living/LivingEquipmentChangeEvent;)V
1479 | 3: ASM: class com.infamous.dungeons_gear.items.armor.ArmorEvents onSpelunkerArmorEquipped(Lnet/minecraftforge/event/entity/living/LivingEquipmentChangeEvent;)V
1480 | 4: ASM: class yesman.epicfight.events.EntityEvents equipChangeEvent(Lnet/minecraftforge/event/entity/living/LivingEquipmentChangeEvent;)V
1481 | 5: ASM: class com.infamous.dungeons_gear.GlobalEvents resetCombo(Lnet/minecraftforge/event/entity/living/LivingEquipmentChangeEvent;)V
1482 | java.lang.NoSuchMethodError: net.minecraft.entity.ai.attributes.ModifiableAttributeInstance.func_142049_d()V
1483 | at yesman.epicfight.capabilities.entity.player.ServerPlayerData.updateHeldItem(ServerPlayerData.java:81)
1484 | at yesman.epicfight.events.EntityEvents.equipChangeEvent(EntityEvents.java:308)
1485 | at net.minecraftforge.eventbus.ASMEventHandler_158_EntityEvents_equipChangeEvent_LivingEquipmentChangeEvent.invoke(.dynamic)
1486 | at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:85)
1487 | at net.minecraftforge.eventbus.EventBus.post(EventBus.java:302)
1488 | at net.minecraftforge.eventbus.EventBus.post(EventBus.java:283)
1489 | at net.minecraft.entity.LivingEntity.func_241354_r_(LivingEntity.java:2268)
1490 | at net.minecraft.entity.LivingEntity.func_241353_q_(LivingEntity.java:2239)
1491 | at net.minecraft.entity.LivingEntity.func_70071_h_(LivingEntity.java:2141)
1492 | at net.minecraft.entity.player.PlayerEntity.func_70071_h_(PlayerEntity.java:223)
1493 | at net.minecraft.entity.player.ServerPlayerEntity.func_71127_g(ServerPlayerEntity.java:404)
1494 | at net.minecraft.network.play.ServerPlayNetHandler.func_73660_a(ServerPlayNetHandler.java:207)
1495 | at net.minecraft.network.NetworkManager.func_74428_b(NetworkManager.java:226)
1496 | at net.minecraft.network.NetworkSystem.func_151269_c(NetworkSystem.java:134)
1497 | at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:865)
1498 | at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:291)
1499 | at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:787)
1500 | at net.minecraft.server.MinecraftServer.func_240802_v_(MinecraftServer.java:642)
1501 | at net.minecraft.server.MinecraftServer.func_240783_a_(MinecraftServer.java:232)
1502 | at java.lang.Thread.run(Thread.java:748)
1503 |
1504 | [28Oct2021 15:59:10.589] [Server thread/FATAL] [net.minecraftforge.common.ForgeMod/]: Preparing crash report with UUID 70c4d90e-705f-4591-9eb0-6b5ad235d9b6
1505 | [28Oct2021 15:59:10.591] [Server thread/WARN] [net.minecraft.network.NetworkSystem/]: Failed to handle packet for /60.48.168.9:43536
1506 | net.minecraft.crash.ReportedException: Ticking player
1507 | at net.minecraft.entity.player.ServerPlayerEntity.func_71127_g(ServerPlayerEntity.java:467) ~[?:?]
1508 | at net.minecraft.network.play.ServerPlayNetHandler.func_73660_a(ServerPlayNetHandler.java:207) ~[?:?]
1509 | at net.minecraft.network.NetworkManager.func_74428_b(NetworkManager.java:226) ~[?:?]
1510 | at net.minecraft.network.NetworkSystem.func_151269_c(NetworkSystem.java:134) ~[?:?]
1511 | at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:865) ~[?:?]
1512 | at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:291) ~[?:?]
1513 | at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:787) ~[?:?]
1514 | at net.minecraft.server.MinecraftServer.func_240802_v_(MinecraftServer.java:642) ~[?:?]
1515 | at net.minecraft.server.MinecraftServer.func_240783_a_(MinecraftServer.java:232) ~[?:?]
1516 | at java.lang.Thread.run(Thread.java:748) [?:1.8.0_292]
1517 | Caused by: java.lang.NoSuchMethodError: net.minecraft.entity.ai.attributes.ModifiableAttributeInstance.func_142049_d()V
1518 | at yesman.epicfight.capabilities.entity.player.ServerPlayerData.updateHeldItem(ServerPlayerData.java:81) ~[epicfight:1.0]
1519 | at yesman.epicfight.events.EntityEvents.equipChangeEvent(EntityEvents.java:308) ~[epicfight:1.0]
1520 | at net.minecraftforge.eventbus.ASMEventHandler_158_EntityEvents_equipChangeEvent_LivingEquipmentChangeEvent.invoke(.dynamic) ~[?:?]
1521 | at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:85) ~[eventbus-4.0.0.jar:?]
1522 | at net.minecraftforge.eventbus.EventBus.post(EventBus.java:302) ~[eventbus-4.0.0.jar:?]
1523 | at net.minecraftforge.eventbus.EventBus.post(EventBus.java:283) ~[eventbus-4.0.0.jar:?]
1524 | at net.minecraft.entity.LivingEntity.func_241354_r_(LivingEntity.java:2268) ~[?:?]
1525 | at net.minecraft.entity.LivingEntity.func_241353_q_(LivingEntity.java:2239) ~[?:?]
1526 | at net.minecraft.entity.LivingEntity.func_70071_h_(LivingEntity.java:2141) ~[?:?]
1527 | at net.minecraft.entity.player.PlayerEntity.func_70071_h_(PlayerEntity.java:223) ~[?:?]
1528 | at net.minecraft.entity.player.ServerPlayerEntity.func_71127_g(ServerPlayerEntity.java:404) ~[?:?]
1529 | ... 9 more
1530 | [28Oct2021 15:59:10.635] [Server thread/INFO] [net.minecraft.network.play.ServerPlayNetHandler/]: N4meL3ss12345 lost connection: Internal server error
1531 | [28Oct2021 15:59:10.636] [Server thread/INFO] [net.minecraft.server.dedicated.DedicatedServer/]: N4meL3ss12345 left the game