PHP Drupal: Blank pages or "white screen of death" (WSOD)

Change the shutdown handler And it works to show error details!

One way to force errors to display is to change the shutdown handler. Add the following code (originally from http://stackoverflow.com/questions/1475297/phps-white-screen-of-death), to the front of index.php:

<?php
// -------------------------------------------------------
// - Display Errors
// -------------------------------------------------------
ini_set('display_errors', 'On');
ini_set('html_errors', 0);
// -------------------------------------------------------
// - Error Reporting
// -------------------------------------------------------
error_reporting(-1);
// -------------------------------------------------------
// - Shutdown Handler
// -------------------------------------------------------
function ShutdownHandler()
{
    if(@is_array($error = @error_get_last()))
    {
        return(@call_user_func_array('ErrorHandler', $error));
    };
    return(TRUE);
};
register_shutdown_function('ShutdownHandler');
// -------------------------------------------------------
// - Error Handler
// -------------------------------------------------------
function ErrorHandler($type, $message, $file, $line)
{
    $_ERRORS = Array(
        0x0001 => 'E_ERROR',
        0x0002 => 'E_WARNING',
        0x0004 => 'E_PARSE',
        0x0008 => 'E_NOTICE',
        0x0010 => 'E_CORE_ERROR',
        0x0020 => 'E_CORE_WARNING',
        0x0040 => 'E_COMPILE_ERROR',
        0x0080 => 'E_COMPILE_WARNING',
        0x0100 => 'E_USER_ERROR',
        0x0200 => 'E_USER_WARNING',
        0x0400 => 'E_USER_NOTICE',
        0x0800 => 'E_STRICT',
        0x1000 => 'E_RECOVERABLE_ERROR',
        0x2000 => 'E_DEPRECATED',
        0x4000 => 'E_USER_DEPRECATED'
    );
    if(!@is_string($name = @array_search($type, @array_flip($_ERRORS))))
    {
        $name = 'E_UNKNOWN';
    };
    return(print(@sprintf("%s Error in file \xBB%s\xAB at line %d: %s\n", $name, @basename($file), $line, $message)));
};
$old_error_handler = set_error_handler("ErrorHandler");
?>