PHP - white screen of death!

Question

Hi everyone,

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. I have been able to solve each and every one of the errors that have caused this, but it have taken seriously way too long time.

PHP error_reporting(E_ALL) & display_errors", 1 is set as well. I even installed Xdebug in hope of getting more output, but no. My logging settings are also working, but nothing is written to the log.

Is there a way to get something informative printed out instead of a complete white screen? It would certainly shorten my time spent on solving the eventual errors that causes this?

Thanks a lot!

Reference: http://stackoverflow.com/questions/2149321/why-does-code-igniter-give-me-a-white-page

Answer 1

If there's a fatal compilation error, then you may well get a blank page. Try doing a

php -l <filename.php>

against your script

Answer 2

Look near the top of /index.php for a call to error_reporting() - and make sure it's not changing your php.ini configuration to something else (besides E_ALL).

And since you didn't mention your php.ini configuration, check to ensure you have error_reporting = E_ALL there as well.

Answer 3

Consider setting PHP's error_log configuration variable -- it can be helpful when you have code setting error_reporting() without your knowledge. Then you can check the error log and see what errors, if any, occurred.

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

Make sure your logs and cache folder inside /system are chmod'ed to 777.

Answer 6

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 7

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 8

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