Overcoming "No authentication handler is configured to handle the scheme: Identity.Application"

This error:

InvalidOperationException: No authentication handler is configured to handle the scheme: Identity.Application

For me, it was because in:

public void Configure

I had simply left out:

app.UseIdentity();

(Which goes just before app.UseMvc(routes => )

Further reading

• One of the answers at: "No authentication handler is configured to handle the scheme: Automatic"