Got the following ProviderException :
The Role Manager feature has not been enabled.
So far so good.
Is there somewher
If you got here because you're using the new ASP.NET Identity UserManager, what you're actually looking for is the RoleManager:
var roleManager = new RoleManager(new RoleStore(new ApplicationDbContext()));
roleManager will give you access to see if the role exists, create, etc, plus it is created for the UserManager