[php] Codeigniter displays a blank page instead of error messages

Another method is to see if you've surpassed the error checking in your code by accident. Search all your code for any instance of error_reporting(). If you call it without parameters, it just returns the current level, and is harmless. If you call it with a parameter, such as 0 (zero), it will turn off error reporting.

You can test for this in CodeIgnitor by looking at their core library under ../system/core/Common.php and finding a section that's at about line 615 that looks like:

if (($severity & error_reporting()) !== $severity)
{
   return;
} 

Add something like:

if (($severity & error_reporting()) !== $severity)
{
   echo "Suppressing errors!";
   return;
} 

and you should be able to trap for surpassed errors, and debug from there.