When I render a certain area on my map (on a server using 14w28a), which I presume is the area with all the command blocks, I get kicked from the game and get this message:

Connection Lost
Internal Exception: io.netty.handler.codec.DecoderException: java.lang.IndexOutOfBoundsException: readerIndex(506215) + length(282880) exceeds writerIndex(592487): UnpooledHeapByteBuf(ridx: 506215, widx: 592487, cap: 592487/592487)