FindByNameAsync System.NullReferenceException: 'Object reference not set to an instance of an object

[easoftwaresanderson]

I'm getting this issue , System.NullReferenceException , when I try find user in this code in the version 1.0.0

var userIdentity = _userManager.FindByNameAsync(user.UserID).Result;

Obs.: My object user and userManager aren't null

Please, Does anyone have any idea?