Obfuscation weird error thing

io.netty.channel.IncompleteFlushException: 0 out of 1 message(s) flushed
        at io.netty.channel.ChannelHandlerUtil.handleFlush(ChannelHandlerUtil.java:135)
        at io.netty.channel.ChannelOutboundMessageHandlerAdapter.flush(ChannelOutboundMessageHandlerAdapter.java:94)
        at io.netty.channel.DefaultChannelHandlerContext.invokeFlush0(DefaultChannelHandlerContext.java:1430)
        at io.netty.channel.DefaultChannelHandlerContext.write0(DefaultChannelHandlerContext.java:1574)
        at io.netty.channel.DefaultChannelHandlerContext.access$2600(DefaultChannelHandlerContext.java:39)
        at io.netty.channel.DefaultChannelHandlerContext$24.run(DefaultChannelHandlerContext.java:1545)
        at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:364)
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:326)
        at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:114)
        at java.lang.Thread.run(Thread.java:722)
Caused by: io.netty.handler.codec.CodecException: net.minecraft.server.v1_5_R3.ReportedException: Exception getting block type in world
        at io.netty.handler.codec.MessageToByteEncoder.flush(MessageToByteEncoder.java:56)
        at io.netty.channel.ChannelHandlerUtil.handleFlush(ChannelHandlerUtil.java:117)
        ... 9 more
Caused by: net.minecraft.server.v1_5_R3.ReportedException: Exception getting block type in world
        at net.minecraft.server.v1_5_R3.World.getTypeId(World.java:237)
        at org.spigotmc.OrebfuscatorManager.hasTransparentBlockAdjacent(OrebfuscatorManager.java:196)
        at org.spigotmc.OrebfuscatorManager.hasTransparentBlockAdjacent(OrebfuscatorManager.java:196)
        at org.spigotmc.OrebfuscatorManager.obfuscate(OrebfuscatorManager.java:121)
        at net.minecraft.server.v1_5_R3.Packet56MapChunkBulk.compress(Packet56MapChunkBulk.java:94)
        at net.minecraft.server.v1_5_R3.Packet56MapChunkBulk.a(Packet56MapChunkBulk.java:175)
        at org.spigotmc.netty.PacketEncoder.encode(PacketEncoder.java:39)
        at org.spigotmc.netty.PacketEncoder.encode(PacketEncoder.java:14)
        at io.netty.handler.codec.MessageToByteEncoder.flush(MessageToByteEncoder.java:52)