getting user name as hash code

I created a user by built in sign up , I  employed smtp setting and varified user by email link ,it got successfully varified 
after then when I am trying to sign in with the same user I am am getting hash code in user name which in return making Memebership user a null object 
in my asp.net memebership code I am getting a hash value in user name 
else if (User.Identity.IsAuthenticated)
{
MembershipUser currUser = null;
string gt = null;
if (HttpContext.Current.User != null)
{
currUser = Membership.GetUser(true);
gt = currUser.Email;
}
while debugging I found (HttpContext.Current.User.Identity).Name   having value  fd794c29-99e7-4285-be92-0d05ce3a66dd
I am getting NULL reference error in  
gt = currUser.Email; any suggestions ?
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