Fatal error: Uncaught Error: Call to undefined function simplexml_load_file() in /srv/intranet/wp-content/plugins/unlimited-addons-for-wpbakery-page-builder/inc_php/framework/settings.class.php:1049 Stack trace: #0 /srv/intranet/wp-content/plugins/unlimited-addons-for-wpbakery-page-builder/inc_php/unitecreator_operations.class.php(44): UniteSettingsUC->loadXMLFile('/srv/intranet/w...') #1 /srv/intranet/wp-content/plugins/unlimited-addons-for-wpbakery-page-builder/inc_php/unitecreator_operations.class.php(28): UCOperations->getGeneralSettingsObject() #2 /srv/intranet/wp-content/plugins/unlimited-addons-for-wpbakery-page-builder/inc_php/unitecreator_helper.class.php(241): UCOperations->getGeneralSettings() #3 /srv/intranet/wp-content/plugins/unlimited-addons-for-wpbakery-page-builder/provider/provider_admin.class.php(625): HelperUC::getGeneralSetting('edit_permission') #4 /srv/intranet/wp-content/plugins/unlimited-addons-for-wpbakery-page-builder/provider/core/provider_core_admin.class.php(92): UniteProviderAdminUC->init() in /srv/intranet/wp-content/plugins/unlimited-addons-for-wpbakery-page-builder/inc_php/framework/settings.class.php on line 1049

Wordpress 5.0.3: 

It was my mistake. I forgot to install the php7.2-xml package.