Ok so I think I know what the problem is but what u must do is to first disable by commenting out the line which returns u to login.php in takelogin.php and the turn on show php errors.
Code:
ini_set('display_startup_errors', 1);
ini_set('display_errors', 1);
error_reporting(-1);
Then try to register again and then see what errors you are getting.
Look currently I dont have a copy of u232 installed on my servers but I think u need to increase the length of passhash or secrets but I could be wrong with what field name it is. Also i seem to remember u need to null another field name.