Fatal error: Uncaught TypeError: spl_autoload_register(): Argument #1 ($callback) must be a valid callback or null, function "oauth2client_php_autoload" not found or invalid function name in C:\xampp\htdocs\wp-content\plugins\google-site-kit\third-party\google\auth\autoload.php:35 Stack trace: #0 C:\xampp\htdocs\wp-content\plugins\google-site-kit\third-party\google\auth\autoload.php(35): spl_autoload_register('oauth2client_ph...') #1 {main} thrown in C:\xampp\htdocs\wp-content\plugins\google-site-kit\third-party\google\auth\autoload.php on line 35