“Error: The site is experiencing technical difficulties.”

At the top of wp-config.php, I have these three lines enabled:

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

We’re doing extensive testing in preparation of moving the site from PHP 5.6x to PHP 7.3x, so I needed these lines to catch EVERY error. We also have WP Debugging turned on.

Ran the command via Linux CLI, and have come across these issues…

Testing compatibility with PHP 7.3.

Error: The site is experiencing technical difficulties.

Notice: Constant DB_NAME already defined in /[REMOVED FOR PRIVACY REASONS]/wp-config.php on line 14

Notice: Constant DB_USER already defined in /[REMOVED FOR PRIVACY REASONS]/wp-config.php on line 17

Notice: Constant DB_PASSWORD already defined in /[REMOVED FOR PRIVACY REASONS]/wp-config.php on line 20

Notice: Constant DB_HOST already defined in /[REMOVED FOR PRIVACY REASONS]/wp-config.php on line 23

Notice: Constant DB_CHARSET already defined in /[REMOVED FOR PRIVACY REASONS]/wp-config.php on line 26

Notice: Constant DB_COLLATE already defined in /[REMOVED FOR PRIVACY REASONS]/wp-config.php on line 29

Notice: Constant AUTH_KEY already defined in /[REMOVED FOR PRIVACY REASONS]/wp-config.php on line 40

Notice: Constant SECURE_AUTH_KEY already defined in /[REMOVED FOR PRIVACY REASONS]/wp-config.php on line 41

Notice: Constant LOGGED_IN_KEY already defined in /[REMOVED FOR PRIVACY REASONS]/wp-config.php on line 42

Notice: Constant NONCE_KEY already defined in /[REMOVED FOR PRIVACY REASONS]/wp-config.php on line 43

Notice: Constant AUTH_SALT already defined in /[REMOVED FOR PRIVACY REASONS]/wp-config.php on line 44

Notice: Constant SECURE_AUTH_SALT already defined in /[REMOVED FOR PRIVACY REASONS]/wp-config.php on line 45

Notice: Constant LOGGED_IN_SALT already defined in /[REMOVED FOR PRIVACY REASONS]/wp-config.php on line 46

Notice: Constant NONCE_SALT already defined in /[REMOVED FOR PRIVACY REASONS]/wp-config.php on line 47

Notice: Constant WP_DEBUG already defined in /[REMOVED FOR PRIVACY REASONS]/wp-config.php on line 65

Notice: Constant WP_DEBUG_LOG already defined in /[REMOVED FOR PRIVACY REASONS]/wp-config.php on line 72

Notice: Undefined index: SERVER_NAME in /[REMOVED FOR PRIVACY REASONS]/wp-includes/rest-api.php on line 378

Notice: Undefined index: HTTP_HOST in /[REMOVED FOR PRIVACY REASONS]/wp-content/plugins/rw-quick-page-and-post-redirects/rw_Quick-PagePost-Redirects.php on line 2011

Fatal error: Call to undefined method PHPCompatibility\PHPCSHelper::findStartOfStatement() in /[REMOVED FOR PRIVACY REASONS]/wp-content/plugins/php-compatibility-checker/vendor/phpcompatibility/php-compatibility/PHPCompatibility/Sniffs/FunctionUse/ArgumentFunctionsReportCurrentValueSniff.php on line 323

The “Fatal Error” is interesting… I was able to use this exact plugin (I’ve been moving it from site to site after deactivating it from its previous site) on other PHP 5.6xx sites, without issues. This is actually the second site where the compatibility checker wasn’t able to complete its tasks.

Note: This is a fairly large site (in terms of DB size and site functionality.