WARNING(2): "require(/data/web/1/000/062/471/254930/htdocs/vendor/symfony/polyfill-mbstring/bootstrap.php): failed to open stream: No such file or directory"

Fatal error: require(): Failed opening required '/data/web/1/000/062/471/254930/htdocs/vendor/symfony/polyfill-mbstring/bootstrap.php' (include_path='.:/usr/local/share/pear') in /data/web/1/000/062/471/254930/htdocs/vendor/composer/autoload_real.php on line 55
COMPILE ERROR(64): "require(): Failed opening required '/data/web/1/000/062/471/254930/htdocs/vendor/symfony/polyfill-mbstring/bootstrap.php' (include_path='.:/usr/local/share/pear')"