Communication Error with print head

[dennispo 6]

A user asked me that there is so often to show the message above.

He sent it to me and it's no error when I print, and then I sent it back, he said it shows error again.

We both use the same print head and communication part.

He is in the north and I am in the south, by the way.

We both reset the wire and connection, but it won't work out.

So how to deal with it? Hope you guys can help me, thanks.