Permisos openx y php.ini

File permission errors have been detected, and must be fixed before you can continue.
To fix the errors on a Linux system, try typing in the following command(s):
sudo chmod -R a+w /var/www/html/openx/var
sudo chmod -R a+w /var/www/html/openx/var/cache
sudo chmod -R a+w /var/www/html/openx/var/plugins
sudo chmod -R a+w /var/www/html/openx/var/templates_compiled
sudo chmod -R a+w /var/www/html/openx/plugins
sudo chmod -R a+w /var/www/html/openx/www/admin/plugins
sudo chmod -R a+w /var/www/html/openx/www/images
For more help, please see the OpenX documentation.

Ampliar en el php.ini

Upload_max _size 1000M

Memory_limits 256M

Post_max_upload