If any mysterious error occurring on your WordPress site or getting just a blank white page then you might be want to know what causing this issue? To know the cause of your broken site you have to enable error reporting, while it was disabled by default.
Open your wp-config.php file and paste below code just after 1st line <?php
error_reporting(E_ALL); ini_set('display_errors', 1);
Now add below code above /* That’s all, stop editing! Happy blogging. */
define( 'WP_DEBUG', true);
Upload newly edited wp-config.php file then go back to the page where your error happening, refresh that, now you can see the error message.