In my own Server, I am in creative mode and used the /kill command.
Note: prior to this i had already used this command just some minutes earlier with no issue.

When my character respawned (not to a bed, just world spawn point) it was my character unable to move other then spin around and just seeing the inside of my own head all around me. tried killing myself again but in the same position. logged off but received error logging back in:

Internal Exception: io.netty.handler.codec.DecoderException:java.lang.IndexOutOfBoundsException:readerIndex(51) + length(2) exceeds writerIndex(51): PooledUnsafeDirectByteBuf(ridx: 51, widx: 51, cap: 51).
Attached below is the server log file of the incident.