CME in Age 4 or 5

[sam-kirby]

CME during world loading -> adding TEs to world:

java.util.ConcurrentModificationException
    at java.util.HashMap$HashIterator.nextNode(HashMap.java:1429)
    at java.util.HashMap$ValueIterator.next(HashMap.java:1458)
    at net.minecraft.world.World.addTileEntities(World.java:1949)
    at net.minecraft.world.chunk.Chunk.onLoad(Chunk.java:856)
    at net.minecraftforge.common.chunkio.ChunkIOProvider.syncCallback(ChunkIOProvider.java:109)
    at net.minecraftforge.common.chunkio.ChunkIOExecutor.tick(ChunkIOExecutor.java:150)
    at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:728)
    at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:668)
    at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:185)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526)
    at java.lang.Thread.run(Thread.java:745)

[09:35:23] [Server thread/INFO] [TES]: ##############################
[09:35:23] [Server thread/INFO] [TES]: Adding tile to world: immersivepetroleum:distillationtower
[09:35:23] [Server thread/INFO] [TES]: Position: BlockPos{x=-433, y=74, z=1741}, Dimension: 0
[09:35:23] [Server thread/INFO] [TES]: #############DONE#############
[09:35:23] [Server thread/INFO] [TES]: ##############################
[09:35:23] [Server thread/INFO] [TES]: Adding tile to world: mekanism:mechanical_pipe
[09:35:23] [Server thread/INFO] [TES]: Position: BlockPos{x=-435, y=70, z=1739}, Dimension: 0
[09:35:23] [Server thread/INFO] [TES]: #############DONE#############
[09:35:23] [Server thread/INFO] [TES]: ##############################
[09:35:23] [Server thread/INFO] [TES]: Adding tile to world: mekanism:mechanical_pipe
[09:35:23] [Server thread/INFO] [TES]: Position: BlockPos{x=-433, y=70, z=1739}, Dimension: 0
[09:35:23] [Server thread/INFO] [TES]: #############DONE#############
[09:35:23] [Server thread/ERROR] [minecraft/MinecraftServer]: Encountered an unexpected exception
java.util.ConcurrentModificationException: null

The last TE to be successfully loaded is a mechanical pipe from Mekanism. This is (x: -432 -> -433) on a chunk boundary - important?

Iterator invalidation during adding TE? Looking for anything that touches Chunk.tileEntities during loading.