If Fatal error: Class ‘DOMDocument’ not found please visit here

Maybe you must before run this commands update your repos or add new repos

PHP extension “mcrypt” must be loaded.
yum –enablerepo remi install php-mcrypt*
PHP extension “gd” must be loaded.
yum –enablerepo remi install php-gd
PHP extension “soap” must be loaded.
yum –enablerepo remi install php-soap
PHP extension “mbstring” must be loaded.
yum –enablerepo remi install php-mbst

after commands please restart your services