The mcrypt extension is missing. Please check your PHP configuration

I just followed the tutorial located at https://www.digitalocean.com/community/articles/how-to-install-linux-apache-mysql-php-lamp-stack-on-ubuntu while fixing multiple other errors that I came across along the way and I'm stuck with one last error. When I log in to phpMyAdmin, there's a huge red error at the bottom saying "The mcrypt extension is missing. Please check your PHP configuration.". I installed everything listed in the tutorial on Ubuntu 13.10 via putty.

Try this:

sudo apt-get install php5-mcrypt
sudo ln -s /etc/php5/conf.d/mcrypt.ini /etc/php5/mods-available
sudo php5enmod mcrypt 
sudo service apache2 restart

I've followed the exact tutorial with OP on digital ocean. The only steps that missing is to

sudo php5enmod mcrypt
sudo service apache2 restart 

and the error gone after restarting the apache service