How to enable WordPress debug mode?
Find the file wp-config.php It is usually located in the main WordPress folder. You can find it using a FTP client, or your Web Hosting Admin Panel.
Open the file and find this code:
define('WP_DEBUG', false);
Replace it with:
define('WP_DEBUG', true);
Then, save the file. This code will force WordPress to print any PHP error. It can be useful for developers to understand what is the problem, if there's one.