Crash on Server Start after updating. [1.12.2]

[Jophire]

I recently upgraded to the new Farseek update, as well as streams update. However, after doing so, launching the server would result in this error:

`Time: 6/3/18 4:59 AM Description: Exception in server tick loop

java.util.ConcurrentModificationException at java.util.HashMap$HashIterator.nextNode(HashMap.java:1437) at java.util.HashMap$KeyIterator.next(HashMap.java:1461) at net.minecraft.entity.EntityTracker.func_72788_a(EntityTracker.java:290) at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:779) at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:396) 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:745) ` After a bit of sleuthing I pinned the error to this mod.

Some thing to note. I have only experienced this error when upgrading to the newest version on a server that has ran the previous version. Starting a new world does not cause the crash to occur.