title: ASP Identity - AddToRoleAsync
body: <p>I have a problem using the Microsoft AddToRoleAsync() function.
  For usernames where there is a hyphen in them I cannot get it to work successfully. For example:</p>
  
  <pre><code>var user = new ApplicationUser();
  var email = "name-surname@company.com";
  user = await userManager.FindByEmailAsync(email);
  await userManager.AddToRoleAsync(user.Id, "Admin");
  </code></pre>
  
  <p>I don't get an error thrown, the user just doesn't get added to the role and an entry never appears in the AspNetUserRoles.</p>
  
  <p>However, as soon as I remove the hyphen in the email / username the AddToRoleAsync() works perfectly, which seems strange as this function takes an Id and role name.</p>
  
  <p>We have the same value for both the email and username field.</p>
  
  <p>Can anyone help ?</p>