Fatal error: Uncaught TypeError: Return value of Composer\Autoload\ClassLoader::initializeIncludeClosure() must be an instance of Composer\Autoload\void, none returned in /www/htdocs/w0170b21/eventusfachschule.de/wp-content/plugins/meta-box/vendor/composer/ClassLoader.php:580 Stack trace: #0 /www/htdocs/w0170b21/eventusfachschule.de/wp-content/plugins/meta-box/vendor/composer/ClassLoader.php(112): Composer\Autoload\ClassLoader::initializeIncludeClosure() #1 /www/htdocs/w0170b21/eventusfachschule.de/wp-content/plugins/meta-box/vendor/composer/autoload_real.php(26): Composer\Autoload\ClassLoader->__construct('/www/htdocs/w01...') #2 /www/htdocs/w0170b21/eventusfachschule.de/wp-content/plugins/meta-box/vendor/autoload.php(25): ComposerAutoloaderInit66983e14f2631207071f6f30c7c3de9c::getLoader() #3 /www/htdocs/w0170b21/eventusfachschule.de/wp-content/plugins/meta-box/inc/loader.php(65): require('/www/htdocs/w01...') #4 /www/htdocs/w0170b21/eventusfachschule.de/wp-content/plugins/meta-box/meta-box.php(19): RWMB_Loader->init() # in /www/htdocs/w0170b21/eventusfachschule.de/wp-content/plugins/meta-box/vendor/composer/ClassLoader.php on line 580