White screen of death!

Question

After debugging a codeigniter app that were installed into a new development environment, I have started to freak out when seeing white screens with nothing more available.

Answer 1

The best thing is to have a checklist of the common problems that could cause this since CI's default is already

error_reporting(E_ALL);

1. Same name controllers and models
2. using reserved words as methods

list goes on..

Answer 2

Have you by chance happen to create a cached output for that particular method inside your controller. Because if so, then it may create a cached version of the page and practically that page is not even running. The cached error output page is showing up. Please check your cache folder inside the application. It should only contain the index.html file.

Answer 3

Grep the files for 'error_reporting', and 'display_errors', the application might turn it off somewhere.

Also, to be able to see parse errors, you need to set error_reporting/display_errors in the php.ini file, or a .htaccess file, setting it in the script files will not do, and will lead to the white page you describe if there are parsing errors.

Answer 4

Ensure that there's no whitespace in your files output outside of the CI buffer, especially if compression is turned on. You can test this by turning off compression in your CI config file.

See step two at: http://codeigniter.com/user_guide/installation/upgrade_141.html (Note that while this is for the upgrade, it contains a snippet of the config file which explains the problem.)

Answer 5

Aside from everything else posted, also make sure that something masked with the @ (error suppression operator) isn't throwing a fatal error.

Answer 6

I had this problem on my freshly installed server. Debian 7. I enabled logging, error reporting, disabled gzip and so on.

However, my PHP-installation did not have MySQL enabled. Enabling MySQL did the trick for me.