If you set error_reporting to an applicable level, then an error should be displayed if you have display_errors turned on, or else logged to your PHP error log (much preferable for the production version, of course). For a quick debug, add this to the code anywhere before the call:
ini_set('display_errors', 1);
error_reporting(E_ALL);
Also, for the above to work, make sure you are not suppressing errors via a "@" before the file_get_contents() call.