I just experienced this error in Visual studio with a sole button to “close visual studio”.
It happened on opening projects. I ended up having to log out of my MSDN account on that same error window and back in again before it would allow me forward.
Clicking the “Check for an updated license” only worked after that logout and in process.
Seems others have seen this too Visual Studio 2015 fails to check license (unable to save downloaded online license)
I wonder if it is a transient connectivity issue with license webservices or a deeper issue of some kind.