Getting Laravel error while hosting on shared hosting

Warning: require(/storage/ssd1/943/12963943/public_html/vendor/composer/../symfony/polyfill-mbstring/bootstrap.php): failed to open stream: No such file or directory in /storage/ssd1/943/12963943/public_html/vendor/composer/autoload_real.php on line 66

Warning: require(/storage/ssd1/943/12963943/public_html/vendor/composer/../symfony/polyfill-mbstring/bootstrap.php): failed to open stream: No such file or directory in /storage/ssd1/943/12963943/public_html/vendor/composer/autoload_real.php on line 66

Fatal error: require(): Failed opening required '/storage/ssd1/943/12963943/public_html/vendor/composer/../symfony/polyfill-mbstring/bootstrap.php' (include_path='.:/usr/share/pear:/usr/share/php') in /storage/ssd1/943/12963943/public_html/vendor/composer/autoload_real.php on line 66

via Chebli Mohamed