This message is thrown by WordPress when there is an error in user registration.
1.To see the actual error thrown by wordpress,go to \wordpress\wp-content\plugins\miniorange-login-openid\class-mo-openid-login-widget.php file.
2.Search for the line:
//print_r($user_id);
3.Change it to
print_r($user_id);
4. Save the file and try logging again. please send us the error you while logging in through the support forum to your right.