[13:09:19] [Client thread/ERROR] [FML]: Exception caught during firing event net.minecraftforge.fml.common.gameevent.TickEvent$RenderTickEvent@14cb5250:
java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextNode(Unknown Source) ~[?:1.8.0_71]
	at java.util.HashMap$EntryIterator.next(Unknown Source) ~[?:1.8.0_71]
	at java.util.HashMap$EntryIterator.next(Unknown Source) ~[?:1.8.0_71]
	at <PROFILE NAME>.ironbackpacks.entity.EntityBackpack.updateBackpacks(EntityBackpack.java:84) ~[EntityBackpack.class:1.8.9-2.0.1]
	at <PROFILE NAME>.ironbackpacks.events.ClientEventHandler.preRenderTick(ClientEventHandler.java:42) ~[ClientEventHandler.class:1.8.9-2.0.1]
	at <PROFILE NAME>.ironbackpacks.events.ClientEventHandler.onRenderTickStart(ClientEventHandler.java:29) ~[ClientEventHandler.class:1.8.9-2.0.1]
	at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_6_ClientEventHandler_onRenderTickStart_RenderTickEvent.invoke(.dynamic) ~[?:?]
	at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:55) ~[ASMEventHandler.class:?]
	at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:140) [EventBus.class:?]
	at net.minecraftforge.fml.common.FMLCommonHandler.onRenderTickStart(FMLCommonHandler.java:340) [FMLCommonHandler.class:?]
	at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:1049) [ave.class:?]
	at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:349) [ave.class:?]
	at net.minecraft.client.main.Main.main(SourceFile:124) [Main.class:?]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_71]
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_71]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_71]
	at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_71]
	at net.minecraft.launchwrapper.Launch.launch(Launch.java:135) [launchwrapper-1.12.jar:?]
	at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.12.jar:?]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_71]
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_71]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_71]
	at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_71]
	at org.multimc.onesix.OneSixLauncher.launchWithMainClass(OneSixLauncher.java:310) [NewLaunch.jar:?]
	at org.multimc.onesix.OneSixLauncher.launch(OneSixLauncher.java:395) [NewLaunch.jar:?]
	at org.multimc.EntryPoint.listen(EntryPoint.java:170) [NewLaunch.jar:?]
	at org.multimc.EntryPoint.main(EntryPoint.java:54) [NewLaunch.jar:?]
[13:09:19] [Client thread/ERROR] [FML]: Index: 1 Listeners:
[13:09:19] [Client thread/ERROR] [FML]: 0: NORMAL
[13:09:19] [Client thread/ERROR] [FML]: 1: ASM: <PROFILE NAME>.ironbackpacks.events.ClientEventHandler@219c10c2 onRenderTickStart(Lnet/minecraftforge/fml/common/gameevent/TickEvent$RenderTickEvent;)V