The software exits after typing the ROOT password.

The most probable reason is your user account is not able to invoke the SUDO command.

1. Please install visudo package, and launch it
2. At the end of the editable file, add this line (replace toto by tour login):
   ## Same thing without a password # %wheel ALL=(ALL) NOPASSWD: ALL toto ALL=(ALL) PASSWD: ALL
3. To edit press Esc +i
4. To save, press Esc, then type :wq (with the two small dots!)
5. Restart your computer...