MATEKH743 wing running arduplane 4.1.0beta5 , connecting with 1.3.75 build of MP .
I did a clean firmware install including full chip erase .
I m getting a missing parameter error upon connection to MP .
At this point Ive done nothing with any settings .I had similair troubles with previous beta versions of 4.1.0
Sorry for my unsophisticated answer. I had a similar issue. But after setting some parameters using https://ardupilot.org/mavproxy/ the problem went away.