How to activate WP_DEBUG (debug mode) in WordPress
WP_DEBUG is a PHP constant (a permanent global variable) that can be used to trigger the “debug” mode throughout WordPress. It is assumed to be false by default and is usually set to true in the wp-config.php file on development copies of WordPress.
In order to make your WordPress installation show the errors you are getting from a theme or plugin, you can activate it. Note that this is not recommended to live websites as users will see the errors, but in case you need to debug your website and see why it is crashing or what could be causing the issue, the first step would be to check the debug mode.
You can be asked by some of our representatives to activate the debug, as there are cases when the support team can’t really guess what could be the problem.
In order to do that, you’ll have to connect to your server via FTP, edit the wp-config.php file there and find the line:
define( 'WP_DEBUG', false );
and basically change the “false” declaration to true.
Once we have debugged and fixed the issue, it is recommended to set it back to false.