Used a Command Block in a mine-cart, Then put Give tnt 64 to a player turned it on and now my server wont work

Internal Exception: IO.netty.handler.codec.DecoderException: JavaioIOEcexption: The recievied string lengh is longer then macimum alloud (95 > 64)

it says This every time You connect,

I also Tried turning command blocks off, Still after a restart if u try to connect again same error.

i tryed a downgrade and still throwing same error