@e selector causes disconnect

While connected to a LAN game with cheats enabled, using /kill @e[type!=Player] and later using the /say @e command causes the game to loose connection. This is the error:
Connection Lost
Internal Exception: io.netty.handler.codec.DecoderException:
java.langIndexOutOfBoundsException: readerIndex(1) + length(1)
exceeds writerIndex(1): UnpooledHeapByteBuf(ridx: 1, widx:1, cap: 1)