Enabling the error reporting on the server

Error reporting on WordPress

Enabling error reporting

Write this code inside your wp-config.php file right under the <?php part:

error_reporting(E_ALL);
ini_set('display_errors', 1);
ini_set("log_errors", 1);
ini_set("error_log", dirname(__FILE__)."/php-error.log");

Then take a look on your messed up website. Probably the error will be written out, but if not, php-error.log file should also appear in the root folder of your site (http://example.com/php-error.log).

You should look for Fatal errors, and you will see, if comes from a plugin or the server. You can also just try to deactivate your plugins one by one, maybe you will find the problem like that too.

Error logging in the WordPress way

Open up your wp-config.php file and change the WP_DEBUG value to true:

define( 'WP_DEBUG', true );

If you go to the page, where you see the "There has been a critical error on your website." message, WordPress should create a log file containing the error message: /wp-content/debug.log

You should look for Fatal errors, and you will see, if comes from a plugin or the server. You can also just try to deactivate your plugins one by one, maybe you will find the problem like that too. If for some reason you wouldn't see anything, try this method.

Error reporting on Joomla

Error logging in the Joomla way

Go to System → Global Configuration → Server tab and switch the Error Reporting to Maximum

Then go to the page where you had the error. It should write out an error or more, but probably only one of them is the real error, which is causing the other ones. These are usually server side configuration issues, like PHP is missing a basic library, or the memory limit, nesting level is too low, and your server host can help you with that. If you are not sure, just Google the Fatal error message, and you will know, what it means.

Deeper error logging

Sometimes turning on Joomla's Error reporting does not give an accurate error message. In that case you could try creating an error log. Copy the following code for example, to /libraries/smartslider3/joomla.php:

error_reporting(E_ALL);
ini_set('display_errors', 1);
ini_set("log_errors", 1);
ini_set("error_log", dirname(__FILE__)."/php-error.log");
	

Then check the page where you see the error. If you visit the /libraries/smartslider3/ folder again, you should find a php-error.log file there containing more details about the problem.