Pack: Sevtech 3.1.5
Spongeforge: 1.12.2-2838-7.2.4-RC4059
Forge: 1.12.2-14.23.5.2854-universal
Nucleus: 1.14.6-S7.1-MC1.12.2
OreExcavation Integration: 2.3.4

When a player uses a Tinker's tool with Excavate on a mob it crashes the server. When they log back on after restart the entire server lags. Does not affect the enchant on vanilla tools.

020-08-21 05:07:28 | [threadlock]: Status: RUNNABLE
2020-08-21 05:07:28 | [threadlock]: Stacktrace:
2020-08-21 05:07:28 | [threadlock]: - java.io.DataInputStream.readFully(DataInputStream.java:195)
2020-08-21 05:07:28 | [threadlock]: - java.io.DataInputStream.readUTF(DataInputStream.java:609)
2020-08-21 05:07:28 | [threadlock]: - java.io.DataInputStream.readUTF(DataInputStream.java:564)
2020-08-21 05:07:28 | [threadlock]: - net.minecraft.nbt.NBTTagString.func_152446_a(NBTTagString.java:31)
2020-08-21 05:07:28 | [threadlock]: - net.minecraft.nbt.NBTTagList.func_152446_a(NBTTagList.java:63)
2020-08-21 05:07:28 | [threadlock]: - net.minecraft.nbt.NBTTagCompound.func_152449_a(NBTTagCompound.java:497)
2020-08-21 05:07:28 | [threadlock]: - net.minecraft.nbt.NBTTagCompound.func_152446_a(NBTTagCompound.java:58)
2020-08-21 05:07:28 | [threadlock]: - net.minecraft.nbt.NBTTagCompound.func_152449_a(NBTTagCompound.java:497)
2020-08-21 05:07:28 | [threadlock]: - net.minecraft.nbt.NBTTagCompound.func_152446_a(NBTTagCompound.java:58)
2020-08-21 05:07:28 | [threadlock]: - net.minecraft.nbt.NBTTagCompound.func_152449_a(NBTTagCompound.java:497)
2020-08-21 05:07:28 | [threadlock]: - net.minecraft.nbt.NBTTagCompound.func_152446_a(NBTTagCompound.java:58)
2020-08-21 05:07:28 | [threadlock]: - net.minecraft.nbt.CompressedStreamTools.func_152455_a(CompressedStreamTools.java:133)
2020-08-21 05:07:28 | [threadlock]: - net.minecraft.nbt.CompressedStreamTools.func_152456_a(CompressedStreamTools.java:88)
2020-08-21 05:07:28 | [threadlock]: - net.minecraft.nbt.CompressedStreamTools.func_74796_a(CompressedStreamTools.java:31)
2020-08-21 05:07:28 | [threadlock]: - org.spongepowered.common.entity.player.SpongeUser.initialize(SpongeUser.java:171)
2020-08-21 05:07:28 | [threadlock]: - org.spongepowered.common.entity.player.SpongeUser.getDataHolder(SpongeUser.java:133)
2020-08-21 05:07:28 | [threadlock]: - org.spongepowered.common.entity.player.SpongeUser.get(SpongeUser.java:1109)
2020-08-21 05:07:28 | [threadlock]: - io.github.nucleuspowered.nucleus.modules.vanish.listener.VanishListener.lambda$null$0(VanishListener.java:48)
2020-08-21 05:07:28 | [threadlock]: - io.github.nucleuspowered.nucleus.modules.vanish.listener.VanishListener$$Lambda$5890/1611007664.apply(Unknown Source)
2020-08-21 05:07:28 | [threadlock]: - java.util.Optional.map(Optional.java:215)
2020-08-21 05:07:28 | [threadlock]: - io.github.nucleuspowered.nucleus.modules.vanish.listener.VanishListener.lambda$onAuth$3(VanishListener.java:48)
2020-08-21 05:07:28 | [threadlock]: - io.github.nucleuspowered.nucleus.modules.vanish.listener.VanishListener$$Lambda$5881/1010033506.run(Unknown Source)
2020-08-21 05:07:28 | [threadlock]: - org.spongepowered.api.scheduler.Task$Builder.lambda$execute$0(Task.java:139)
2020-08-21 05:07:28 | [threadlock]: - org.spongepowered.api.scheduler.Task$Builder$$Lambda$486/341035890.accept(Unknown Source)
2020-08-21 05:07:28 | [threadlock]: - org.spongepowered.common.scheduler.SchedulerBase.lambda$startTask$0(SchedulerBase.java:197)
2020-08-21 05:07:28 | [threadlock]: - org.spongepowered.common.scheduler.SchedulerBase$$Lambda$713/1708853355.run(Unknown Source)
2020-08-21 05:07:28 | [threadlock]: - org.spongepowered.common.scheduler.SyncScheduler.executeTaskRunnable(SyncScheduler.java:74)
2020-08-21 05:07:28 | [threadlock]: - org.spongepowered.common.scheduler.SchedulerBase.startTask(SchedulerBase.java:188)
2020-08-21 05:07:28 | [threadlock]: - org.spongepowered.common.scheduler.SchedulerBase.processTask(SchedulerBase.java:174)
2020-08-21 05:07:28 | [threadlock]: - org.spongepowered.common.scheduler.SchedulerBase$$Lambda$711/551129620.accept(Unknown Source)
2020-08-21 05:07:28 | [threadlock]: - java.util.concurrent.ConcurrentHashMap$ValuesView.forEach(ConcurrentHashMap.java:4707)
2020-08-21 05:07:28 | [threadlock]: - org.spongepowered.common.scheduler.SchedulerBase.runTick(SchedulerBase.java:112)
2020-08-21 05:07:28 | [threadlock]: - org.spongepowered.common.scheduler.SyncScheduler.tick(SyncScheduler.java:47)
2020-08-21 05:07:28 | [threadlock]: - org.spongepowered.common.scheduler.SpongeScheduler.tickSyncScheduler(SpongeScheduler.java:189)
2020-08-21 05:07:28 | [threadlock]: - org.spongepowered.mod.SpongeMod.onTick(SpongeMod.java:441)
2020-08-21 05:07:28 | [threadlock]: - net.minecraftforge.fml.common.eventhandler.ASMEventHandler_710_SpongeMod_onTick_ServerTickEvent.invoke(.dynamic)
2020-08-21 05:07:28 | [threadlock]: - net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
2020-08-21 05:07:28 | [threadlock]: - net.minecraftforge.fml.common.eventhandler.EventBus.forgeBridge$post(EventBus.java:756)
2020-08-21 05:07:28 | [threadlock]: - net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:706)
2020-08-21 05:07:28 | [threadlock]: - net.minecraftforge.fml.common.FMLCommonHandler.onPreServerTick(FMLCommonHandler.java:279)
2020-08-21 05:07:28 | [threadlock]: - net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:657)
2020-08-21 05:07:28 | [threadlock]: - net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526)
2020-08-21 05:07:28 | [threadlock]: - java.lang.Thread.run(Thread.java:748)
2020-08-21 05:07:28 | §9-#-#-#- END THREAD LOCKSMITH -#-#-#-§r

Here is a player file where the excavate caused the file to leak/overload:
huge-player-file.zip