I Downloaded VS 2017 & NC 4.0 . I also installed Test Dapater for Nunit3.0 in Extension and Updates but the test explorer just wont show the unit tests as it was with 3.9 on vs2015 .
I also got the same issue, tried following steps and it worked:
1. Update Visual Studio to latest version. 2. Install "Nunit 3.0 test adapter" from Extension and Updates. 3. Go to Test --> Test Settings --> Default Process Architecture --> Select x86 or x64 (if not selected) 4. Close ALL instances of Visual Studio and re-run, build the project. Test cases will appear in test explorer.