Same problem here on MacOs. MySteinberg Id works (verified on Transit iOS App), but in Cubase 8.5 I can’t get past the login window. Same procedure as vinja. I updated my eLicenser, registered it again so that the website says it contains a license for VST Transit, but nothin happens when I try to login besides the short cursor spin. No log, no error … 
The status bar on the bottom of the VST Transit window displays nothing but an (X) to the right, as if it is trying to connect and I could abort that. (just like in web browsers).