Microsoft has launched CU for Skype for Business server, this time Mars 2018. This gives build
You can download it here Latest CU Mars 2018
Since my last blogpost about the Desember 2017 this might be one for you. I am about to try it out now. If I find something about it. Be sure to read about it here.
After installing it the error contains screen sharing isn't allowed for this contact is now gone.