Description: Ticking entity

java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901)
	at java.util.ArrayList$Itr.next(ArrayList.java:851)
	at net.minecraft.server.v1_8_R1.EntityLightning.s_(EntityLightning.java:75)
	at net.minecraft.server.v1_8_R1.World.tickEntities(World.java:1352)
	at net.minecraft.server.v1_8_R1.WorldServer.tickEntities(WorldServer.java:576)
	at net.minecraft.server.v1_8_R1.MinecraftServer.z(MinecraftServer.java:772)
	at net.minecraft.server.v1_8_R1.DedicatedServer.z(DedicatedServer.java:316)
	at net.minecraft.server.v1_8_R1.MinecraftServer.y(MinecraftServer.java:634)
	at net.minecraft.server.v1_8_R1.MinecraftServer.run(MinecraftServer.java:537)
	at java.lang.Thread.run(Thread.java:745)


A detailed walkthrough of the error, its code path and all known details is as follows:
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-- Head --
Stacktrace:
	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901)
	at java.util.ArrayList$Itr.next(ArrayList.java:851)
	at net.minecraft.server.v1_8_R1.EntityLightning.s_(EntityLightning.java:75)

-- Entity being ticked --
Details:
	Entity Type: null (net.minecraft.server.v1_8_R1.EntityLightning)
	Entity ID: 5517814
	Entity Name: unknown
	Entity's Exact location: -2513.04, 75.00, 115.63
	Entity's Block location: -2514.00,75.00,115.00 - World: (-2514,75,115), Chunk: (at 14,4,3 in -158,7; contains blocks -2528,0,112 to -2513,255,127), Region: (-5,0; contains chunks -160,0 to -129,31, blocks -2560,0,0 to -2049,255,511)
	Entity's Momentum: 0.00, 0.00, 0.00
	Entity's Rider: ~~ERROR~~ NullPointerException: null
	Entity's Vehicle: ~~ERROR~~ NullPointerException: null
Stacktrace:
	at net.minecraft.server.v1_8_R1.World.tickEntities(World.java:1352)
	at net.minecraft.server.v1_8_R1.WorldServer.tickEntities(WorldServer.java:576)