Diagnosing PHP or Script Errors
If you are ever presented with a blank page instead of your expected content, this can be attributed to a PHP coding issue.
To diagnose the cause of the error you can enable PHP error displays via the following directive in your .htaccess file:
php_value display_errors on
After adding the above line to your .htaccess, visit the same page again or same URL and you should see the error message which will indicate where you should look to resolve the issue. If no error is displayed and you still see a white page, look to your particular script documentation for how to enable PHP error display for your script.
This is also recommended if some portion of your script(s) are not doing what they should be doing, for instance a module not displaying when it has been enabled.