Permission of the /media folder

  • chown -R www-data:www-data /var/www/magento
  • chmod -R 775 /var/www/magento

mcrypt extension

  • sudo apt-get install php5-mcrypt
  • php5enmod mcrypt

gd extension

  • sudo apt-get install php5-gd
  • php5enmod gd

remember to restart

  • service apache2 restart