1. Can you put a break point inside Login1_Authenticate that is defined under
void Login1_Authenticate(object sender, AuthenticateEventArgs e)
e.Authenticated = UserManager.Default.ValidateUser(this.Login1.UserName, this.Login1.Password);
and see whether the use is validated?
Have you change the passwordFormat parameter of the membership provider in the web.config?
2. Check this article
3. Create a new user programmatically and add it to administrators role.
the Telerik team
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