Unable to Install

Hello

We are trying to install this plugin in our website but it show error below

Warning: require(/home/sites/19a/7/73504aaeda/public_html/wp-content/plugins/app-builder/vendor/symfony/polyfill-mbstring/bootstrap80.php): Failed to open stream: No such file or directory in /home/sites/19a/7/73504aaeda/public_html/wp-content/plugins/app-builder/vendor/symfony/polyfill-mbstring/bootstrap.php on line 15

Fatal error: Uncaught Error: Failed opening required '/home/sites/19a/7/73504aaeda/public_html/wp-content/plugins/app-builder/vendor/symfony/polyfill-mbstring/bootstrap80.php' (include_path='.:/usr/share/pear') in /home/sites/19a/7/73504aaeda/public_html/wp-content/plugins/app-builder/vendor/symfony/polyfill-mbstring/bootstrap.php:15 Stack trace: #0 /home/sites/19a/7/73504aaeda/public_html/wp-content/plugins/app-builder/vendor/composer/autoload_real.php(71): require() #1 /home/sites/19a/7/73504aaeda/public_html/wp-content/plugins/app-builder/vendor/composer/autoload_real.php(61): composerRequire1832d6d7b4498126bedeca495c573509('0e6d7bf4a5811bf...', '/home/sites/19a...') #2 /home/sites/19a/7/73504aaeda/public_html/wp-content/plugins/app-builder/vendor/autoload.php(7): ComposerAutoloaderInit1832d6d7b4498126bedeca495c573509::getLoader() #3 /home/sites/19a/7/73504aaeda/public_html/wp-content/plugins/app-builder/app-builder.php(37): require_once('/home/sites/19a...') #4 /home/sites/19a/7/73504aaeda/public_html/wp-admin/includes/plugin.php(2286): include_once('/home/sites/19a...') #5 /home/sites/19a/7/73504aaeda/public_html/wp-admin/plugins.php(191): plugin_sandbox_scrape('app-builder/app...') #6 {main} thrown in /home/sites/19a/7/73504aaeda/public_html/wp-content/plugins/app-builder/vendor/symfony/polyfill-mbstring/bootstrap.php on line 15

Can you Please Help on it

Regards
Atul