[MC-89127] Netty Epoll Server IO #26/ERROR

While cloning large amounts of blocks (About 4 chunks) from loaded chunks to an area around active players this causes random player disconnects.

With only one player on the server this is a non-issue.

Only affects clients when multiple are connected around the clones output area.

Server Error

[Netty Epoll Server IO #26/ERROR]: io.netty.util.IllegalReferenceCountException: refCnt: 0

Client Error

java.util.concurrent.ExecutionException: java.lang.IndexOutOfBoundsException: readerIndex(0) + length(1) exceeds writerIndex(0): UnpooledHeapByteBuf(ridx: 0, widx: 0, cap: 69888/69888)
	at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[?:1.8.0_25]
	at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[?:1.8.0_25]
	at g.a(SourceFile:46) [15w38b.jar:?]
	at bab.as(SourceFile:920) [15w38b.jar:?]
	at bab.a(SourceFile:377) [15w38b.jar:?]
	at net.minecraft.client.main.Main.main(SourceFile:125) [15w38b.jar:?]
Caused by: java.lang.IndexOutOfBoundsException: readerIndex(0) + length(1) exceeds writerIndex(0): UnpooledHeapByteBuf(ridx: 0, widx: 0, cap: 69888/69888)
	at io.netty.buffer.AbstractByteBuf.checkReadableBytes(AbstractByteBuf.java:1175) ~[netty-all-4.0.23.Final.jar:4.0.23.Final]
	at io.netty.buffer.AbstractByteBuf.readByte(AbstractByteBuf.java:570) ~[netty-all-4.0.23.Final.jar:4.0.23.Final]
	at em.readByte(SourceFile:663) ~[15w38b.jar:?]
	at aqw.a(SourceFile:87) ~[15w38b.jar:?]
	at ard.a(SourceFile:908) ~[15w38b.jar:?]
	at bif.a(SourceFile:522) ~[15w38b.jar:?]
	at gp.a(SourceFile:68) ~[15w38b.jar:?]
	at gp.a(SourceFile:11) ~[15w38b.jar:?]
	at fh$1.run(SourceFile:13) ~[15w38b.jar:?]
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[?:1.8.0_25]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[?:1.8.0_25]
	at g.a(SourceFile:45) ~[15w38b.jar:?]
	... 3 more

Per Lorgon111

Internal Exception: io.netty.handler.codec.DecoderException: java.lang.IndexOutOfBoundsException: readerIndix(13) + length(6684) exceeds writerIndex(13); UnpooledHeapyByteBuf(ridx: 13, widx: 13, cap: 13)