Warning: require(/var/www/html/DEV/vendor/symfony/polyfill-mbstring/bootstrap.php): failed to open stream: No such file or directory in /var/www/html/DEV/vendor/composer/autoload_real.php on line 60

Fatal error: require(): Failed opening required '/var/www/html/DEV/vendor/symfony/polyfill-mbstring/bootstrap.php' (include_path='/var/www/html/DEV/vendor/phpunit/php-file-iterator:/var/www/html/DEV/vendor/phpunit/phpunit:/var/www/html/DEV/vendor/symfony/yaml:/var/www/html/DEV/vendor/magento/zendframework1/library:.:/usr/share/php') in /var/www/html/DEV/vendor/composer/autoload_real.php on line 60