Forge 1.12.2 Server crashing

So, i have a forge 1.12.2 server. First 5-10 minutes I can play normally, but then the server just crashes, and always for the same unknown reason, can anyone help me?


Description: Exception in server tick loop

java.util.ConcurrentModificationException
    at java.util.HashMap$HashIterator.nextNode(Unknown Source)
    at java.util.HashMap$EntryIterator.next(Unknown Source)
    at java.util.HashMap$EntryIterator.next(Unknown Source)
    at com.wonderfulenchantments.enchantments.PhoenixDiveEnchantment.onUpdate(PhoenixDiveEnchantment.java:120)
    at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_506_PhoenixDiveEnchantment_onUpdate_WorldTickEvent.invoke(.dynamic)
    at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
    at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:182)
    at net.minecraftforge.fml.common.FMLCommonHandler.onPreWorldTick(FMLCommonHandler.java:287)
    at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:752)
    at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:397)
    at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:668)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526)
    at java.lang.Thread.run(Unknown Source)