Fatal error: Uncaught TypeError: Return value of Composer\Autoload\ClassLoader::initializeIncludeClosure() must be an instance of Composer\Autoload\void, none returned in /wp-content/plugins/meta-box/vendor/composer/ClassLoader.php:580 Stack trace: #0 /wp-content/plugins/meta-box/vendor/composer/ClassLoader.php(112): Composer\Autoload\ClassLoader::initializeIncludeClosure() #1 /wp-content/plugins/meta-box/vendor/composer/autoload_real.php(26): Composer\Autoload\ClassLoader->__construct('/wp-content/plu...') #2 /wp-content/plugins/meta-box/vendor/autoload.php(25): ComposerAutoloaderInit66983e14f2631207071f6f30c7c3de9c::getLoader() #3 /wp-content/plugins/meta-box/inc/loader.php(65): require('/wp-content/plu...') #4 /wp-content/plugins/meta-box/meta-box.php(19): RWMB_Loader->init() #5 /wp-settings.php(409): include_once('/wp-content/plu...') #6 /wp-config.php(88): require_once('/wp-settings.ph...') #7 /wp-load.php(50): require_once('/wp-config.php') #8 /wp-blog-header.php(13): require_once('/wp-load.php') #9 /index.php(17): in /wp-content/plugins/meta-box/vendor/composer/ClassLoader.php on line 580