Try to addScoped abstract class

[markusvt]

I just came across the following problem:

In the Startup.cs in the configureServices Method I added the following line
services.AddScoped();

When I tried to start the application locally, the Browser only showed "Please wait" and when trying to debug the whole IIS crashed.
I looked into it an saw, that my GenericRepository was accidentally marked as abstract. So I removed that and all worked fine.

Maybe it is possible for you to throw an Exception in such a case, so that not the whole IIS crashes on such a developer error.

[pranavkm]

Dup of aspnet/Tooling#363. You should see an exception if you're running this via kestrel.