Playsound Causes Server Kick

Whenever trying to execute any /playsound in a 1.9 spigot server, the server immediatly kicks the executer with the message:
InternalException: io.netty.handler.codec.decoderexception: java.lang.indexoutofboundsexception: readerindex(24) + length(1) exceeds writerindex(24): unpooledheapbytebuf(ridx:24, widx: 24, cap: 24)