Crash

---- Minecraft Crash Report ----
// You're mean.

Time: 7/19/19 9:06 AM
Description: Exception ticking world

java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.remove(HashMap.java:1459)
	at net.minecraft.world.gen.ChunkProviderServer.func_73156_b(ChunkProviderServer.java:262)
	at net.minecraft.world.WorldServer.func_72835_b(WorldServer.java:207)
	at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:756)
	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(Thread.java:748)


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

-- Head --
Thread: Server thread
Stacktrace:
	at java.util.HashMap$HashIterator.remove(HashMap.java:1459)
	at net.minecraft.world.gen.ChunkProviderServer.func_73156_b(ChunkProviderServer.java:262)
	at net.minecraft.world.WorldServer.func_72835_b(WorldServer.java:207)

-- Affected level --
Details:
	Level name: world
	All players: 0 total; []
	Chunk stats: ServerChunkCache: 334 Drop: 79
	Level seed: 6239572730519209017
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options:
	Level spawn location: World: (115,71,86), Chunk: (at 3,4,6 in 7,5; contains blocks 112,0,80 to 127,255,95), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 1164792 game time, 803532 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 26933 (now: false), thunder time: 38609 (now: false)
	Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Stacktrace:
	at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:756)
	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(Thread.java:748)

-- System Details --
Details:
	Minecraft Version: 1.12.2
	Operating System: Linux (amd64) version 5.2.1-1.el7.elrepo.x86_64
	Java Version: 1.8.0_212, Oracle Corporation
	Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 187960784 bytes (179 MB) / 519569408 bytes (495 MB) up to 3728736256 bytes (3556 MB)
	JVM Flags: 5 total; -Xmx4000M -Xms128M -XX:+UnlockExperimentalVMOptions -XX:MaxMetaspaceSize=320M -XX:MetaspaceSize=32M
	IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
	FML: MCP 9.42 Powered by Forge 14.23.5.2768 5 mods loaded, 5 mods active
	States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored

	| State     | ID        | Version      | Source                                  | Signature                                |
	|:--------- |:--------- |:------------ |:--------------------------------------- |:---------------------------------------- |
	| UCHIJAAAA | minecraft | 1.12.2       | minecraft.jar                           | None                                     |
	| UCHIJAAAA | mcp       | 9.42         | minecraft.jar                           | None                                     |
	| UCHIJAAAA | FML       | 8.0.99.99    | forge-1.12.2-14.23.5.2768-universal.jar | e3c3d50c7c986df74c645c0ac54639741c90a557 |
	| UCHIJAAAA | forge     | 14.23.5.2768 | forge-1.12.2-14.23.5.2768-universal.jar | e3c3d50c7c986df74c645c0ac54639741c90a557 |
	| UCHIJAAAA | pixelmon  | 7.0.6        | Pixelmon.jar                            | None                                     |

	Loaded coremods (and transformers):
	Profiler Position: N/A (disabled)
	Player Count: 0 / 100; []
	Is Modded: Definitely; Server brand changed to 'fml,forge'
	Type: Dedicated Server (map_server.txt)