I have a functional container, but everytime I shift click the NEI trash can button to remove all the items, the game crashes to the "play multiplayer" screen

 

Here's the crash report:

 

 

[13:44:28] [server thread/ERROR] [FML]: There was a critical exception handling a packet on channel NEI

java.util.ConcurrentModificationException

at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901) ~[?:1.8.0_45]

at java.util.ArrayList$Itr.next(ArrayList.java:851) ~[?:1.8.0_45]

at codechicken.nei.NEIServerUtils.deleteAllItems(NEIServerUtils.java:83) ~[NEIServerUtils.class:?]

at codechicken.nei.NEISPH.handlePacket(NEISPH.java:37) ~[NEISPH.class:?]

at codechicken.lib.packet.PacketCustom$ServerInboundHandler.handle(PacketCustom.java:117) ~[PacketCustom$ServerInboundHandler.class:?]

at codechicken.lib.packet.PacketCustom$CustomInboundHandler.channelRead0(PacketCustom.java:77) ~[PacketCustom$CustomInboundHandler.class:?]

at codechicken.lib.packet.PacketCustom$CustomInboundHandler.channelRead0(PacketCustom.java:64) ~[PacketCustom$CustomInboundHandler.class:?]

at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:98) ~[simpleChannelInboundHandler.class:?]

at io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:337) ~[DefaultChannelHandlerContext.class:?]

at io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:323) ~[DefaultChannelHandlerContext.class:?]

at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:785) ~[DefaultChannelPipeline.class:?]

at io.netty.channel.embedded.EmbeddedChannel.writeInbound(EmbeddedChannel.java:169) ~[EmbeddedChannel.class:?]

at cpw.mods.fml.common.network.internal.FMLProxyPacket.processPacket(FMLProxyPacket.java:86) [FMLProxyPacket.class:?]

at net.minecraft.network.NetworkManager.processReceivedPackets(NetworkManager.java:241) [NetworkManager.class:?]

at net.minecraft.network.NetworkSystem.networkTick(NetworkSystem.java:182) [NetworkSystem.class:?]

at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:726) [MinecraftServer.class:?]

at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:614) [MinecraftServer.class:?]

at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:118) [integratedServer.class:?]

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:485) [MinecraftServer.class:?]

at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:752) [MinecraftServer$2.class:?]

 

 

 

Is there a known cause to this or a way to fix this? Hope this is the right spot to ask that...

It seems like a bug in the NEI codes. ConcurrentModification error means that a List is modified multiple times at the same moment(e.g. when the list is modified while its already getting with modifiied elsewhere). And from the stacktrace it seems like its happening inside NEI only. So I think you need to report this to NEI's creators instead.

 

Maybe it is already fixed in a newer version, so if its possible, try to update as well.