The failure listener delegate which will be called by the underlying framework when the user registration has failed and the reason for failure will be propagated through an error object.
[SMPUserManager setDelegate:self];
SMPUserManager* userManager = [SMPUserManager initializeWithConnection:clientConn];
-(void)userRegistrationFailed:userManager
{
// Error handling using the error object
}
               
            This is true in case of asynchronous user registration only.