Having an error trying to log in my own server "Payload may not be larger than 1048576 bytes".

[XrosGamer]

Created a server and for a whole day I tried to fix an error whenever anyone tried to log in, that being the "Invalid Player Data" error, and for once I could fix it, but after that another error "Internal Exception: io.netty.handler.codec.DecoderException: java.lang.IllegalArgumentException: Payload may not be larger than 1048576 bytes"...

Can anyone help?

Logs here

In case anyone needs, i'll send printscreen of my mods list!