Older PHP applications may require allow_url_include to be enabled which by default is disabled due to security risks involved in using it. It is not possible to enable this feature on a specific account and we will be unable to enable it globally due to the increased security risk on other user accounts. You will need to update your applications to not make use of this option which is disabled by default on php installations and it's recommended value is to remain disabled.
The error message that tells you that you need allow_url_include on is the following:
URL file-access is disabled in the server configuration
If this is your own application and you're accessing files on your own account please use relative directories rather than URL's. For example if you're trying to include the file header.php on a page in your public_html folder and both files are located there you should not be using
include("http://mydomain.com/header.php");
This is slow and inefficient you should use:
include("header.php");
