Warning: require_once(PEAR/PackageFileManager2.php): failed to open stream: No such file or directory in /var/www/html/vendor/ezyang/htmlpurifier/package.php on line 5

Fatal error: require_once(): Failed opening required 'PEAR/PackageFileManager2.php' (include_path='.:/usr/local/webserver/php/lib/php') in /var/www/html/vendor/ezyang/htmlpurifier/package.php on line 5