The error you are seeing is a complaint that Platform Manager 4.0 is npt installed on your development PC. Install eVC 4.0 and it will upgrade your Platform Manager.
No, but the eVC 4.0 install automatically update the Platform Manager first. Evidently Studio.NET does not. You can actually run the eVC install and cancel out once the Platform Manager upgrade has been performed.
Platform Builder is not required.
----------------- Chris Tacke, eMVP Applied Data Support