Posted August 20, 201510 yr Anyone know what would cause this here is the error log. I keep getting this exception when running a dedicated server and it happens sometimes during gameplay. I cannot seem to get it to occur on a consistent basis [20:31:49] [Netty IO #1/ERROR] [FML]: NetworkDispatcher exception io.netty.handler.codec.EncoderException: java.util.ConcurrentModificationException at io.netty.handler.codec.MessageToByteEncoder.write(MessageToByteEncoder.java:129) ~[MessageToByteEncoder.class:?] at io.netty.channel.DefaultChannelHandlerContext.invokeWrite(DefaultChannelHandlerContext.java:644) ~[DefaultChannelHandlerContext.class:?] at io.netty.channel.DefaultChannelHandlerContext.write(DefaultChannelHandlerContext.java:698) ~[DefaultChannelHandlerContext.class:?] at io.netty.channel.DefaultChannelHandlerContext.write(DefaultChannelHandlerContext.java:637) ~[DefaultChannelHandlerContext.class:?] at cpw.mods.fml.common.network.handshake.NetworkDispatcher.write(NetworkDispatcher.java:423) ~[NetworkDispatcher.class:?] at io.netty.channel.DefaultChannelHandlerContext.invokeWrite(DefaultChannelHandlerContext.java:644) ~[DefaultChannelHandlerContext.class:?] at io.netty.channel.DefaultChannelHandlerContext.write(DefaultChannelHandlerContext.java:698) ~[DefaultChannelHandlerContext.class:?] at io.netty.channel.DefaultChannelHandlerContext.writeAndFlush(DefaultChannelHandlerContext.java:688) ~[DefaultChannelHandlerContext.class:?] at io.netty.channel.DefaultChannelHandlerContext.writeAndFlush(DefaultChannelHandlerContext.java:717) ~[DefaultChannelHandlerContext.class:?] at io.netty.channel.DefaultChannelPipeline.writeAndFlush(DefaultChannelPipeline.java:893) ~[DefaultChannelPipeline.class:?] at io.netty.channel.AbstractChannel.writeAndFlush(AbstractChannel.java:239) ~[AbstractChannel.class:?] at net.minecraft.network.NetworkManager$1.run(NetworkManager.java:197) [NetworkManager$1.class:?] at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:354) [singleThreadEventExecutor.class:?] at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:348) [NioEventLoop.class:?] at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:101) [singleThreadEventExecutor$2.class:?] at java.lang.Thread.run(Unknown Source) [?:1.7.0_25] Caused by: java.util.ConcurrentModificationException at java.util.HashMap$HashIterator.nextEntry(Unknown Source) ~[?:1.7.0_25] at java.util.HashMap$KeyIterator.next(Unknown Source) ~[?:1.7.0_25] at net.minecraft.nbt.NBTTagCompound.write(NBTTagCompound.java:33) ~[NBTTagCompound.class:?] at net.minecraft.nbt.NBTTagCompound.func_150298_a(NBTTagCompound.java:472) ~[NBTTagCompound.class:?] at net.minecraft.nbt.NBTTagCompound.write(NBTTagCompound.java:35) ~[NBTTagCompound.class:?] at net.minecraft.nbt.CompressedStreamTools.func_150663_a(CompressedStreamTools.java:158) ~[CompressedStreamTools.class:?] at net.minecraft.nbt.CompressedStreamTools.write(CompressedStreamTools.java:148) ~[CompressedStreamTools.class:?] at net.minecraft.nbt.CompressedStreamTools.compress(CompressedStreamTools.java:88) ~[CompressedStreamTools.class:?] at net.minecraft.network.PacketBuffer.writeNBTTagCompoundToBuffer(PacketBuffer.java:94) ~[PacketBuffer.class:?] at net.minecraft.network.PacketBuffer.writeItemStackToBuffer(PacketBuffer.java:140) ~[PacketBuffer.class:?] at net.minecraft.entity.DataWatcher.writeWatchableObjectToPacketBuffer(DataWatcher.java:289) ~[DataWatcher.class:?] at net.minecraft.entity.DataWatcher.writeWatchedListToPacketBuffer(DataWatcher.java:186) ~[DataWatcher.class:?] at net.minecraft.network.play.server.S1CPacketEntityMetadata.writePacketData(S1CPacketEntityMetadata.java:50) ~[s1CPacketEntityMetadata.class:?] at net.minecraft.util.MessageSerializer.encode(MessageSerializer.java:46) ~[MessageSerializer.class:?] at net.minecraft.util.MessageSerializer.encode(MessageSerializer.java:53) ~[MessageSerializer.class:?] at io.netty.handler.codec.MessageToByteEncoder.write(MessageToByteEncoder.java:111) ~[MessageToByteEncoder.class:?]
August 20, 201510 yr CMEs typically occur when dealing with Collections, usually when one thread is iterating over one and another thread is removing items to that same Collection. From your log, it looks as though you have an entity that might be doing some Collections processing when reading/writing NBT, specifically writeWatchedListToPacketBuffer. Putting that section of code within a synchronized block will probably fix it, or by using Iterators to traverse your list when you are removing entries. http://i.imgur.com/NdrFdld.png[/img]
August 20, 201510 yr Author I think I know what the issue is. How would you add a pickup delay for an EntityItem. I think this will fix the issue
August 20, 201510 yr entityitem#delayBeforeCanPickup = x; // changes to setter in 1.8 http://i.imgur.com/NdrFdld.png[/img]
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