basic authentication 404 status code error

Dear all, 
I am writing to seek help, in understanding where I may be going wrong in the following code below.  I am trying to login as trial user, but it gives a 401 error on the client end.  however, I tried debugging my resapository and it lead me to the following fault in the code  below with a 404 statsus code error. 
ClaimRole user = repository.trial(credentials[0], credentials[1]); ClaimRole user2 = repository.full(credentials[0], credentials[1]); if (user == null || user2 == null) { var resp = new HttpResponseMessage(HttpStatusCode.NotFound) { Content = new StringContent(string.Format("access denied")), }; }// this bracket is highlighted while debugging through which the local window shows 404 status code else { 404 -- i ...