Scoreboard: Internal Exception: io.netty.handler.codec.DecoderException: Java.io.IOException: The received string length is longer than maximum allowed: (56 > 40)

I used some command blocks on my server, and when I activated them my client crashed and when I try to enter my server it says this:

Internal Exception: io.netty.handler.codec.DecoderException: Java.io.IOException: The received string length is longer than maximum allowed: (56 > 40)