If you’ve ever installed Apache and phpMyAdmin on Ubuntu 9.04 and you changed the Apache run user and group to your local user (because it’s a lot easier when developing that way) you will most likely have encountered a WSOD when loading the phpMyAdmin page.
The reason behind this is that the permissions of those files on your system are no longer correct. Luckily this can easily be solved by changing them back. By default Ubuntu creates a group with the same name as your user so if your user name is
foo the group name is most likely also
foo. All we need to do is change the group permissions and everything should work again.
sudo chown root:foo /etc/phpmyadmin/config-db.php sudo chown root:foo /etc/phpmyadmin/htpasswd.setup sudo chown root:foo /var/lib/phpmyadmin/*.inc.php