Hi, I got following error when trying to access installed plugin :
Fatal error: Uncaught Error: Class 'DOMDocument' not found in /home/wokadmin/monstrofun.ch/wp-content/plugins/sitepress-multilingual-cms/classes/xml-config/class-wpml-xml-config-validate.php:67 Stack trace: #0 /home/wokadmin/monstrofun.ch/wp-content/plugins/sitepress-multilingual-cms/classes/xml-config/class-wpml-xml-config-validate.php(51): WPML_XML_Config_Validate->get_xml('<wpml-config>\r\n...') #1 /home/wokadmin/monstrofun.ch/wp-content/plugins/sitepress-multilingual-cms/classes/xml-config/class-wpml-xml-config-validate.php(34): WPML_XML_Config_Validate->from_string('<wpml-config>\r\n...') #2 /home/wokadmin/monstrofun.ch/wp-content/plugins/sitepress-multilingual-cms/classes/xml-config/read/class-wpml-xml-config-read-file.php(18): WPML_XML_Config_Validate->from_file('/home/wokadmin/...') #3 /home/wokadmin/monstrofun.ch/wp-content/plugins/sitepress-multilingual-cms/classes/xml-config/class-wpml-config.php(306): WPML_XML_Config_Read_File->get() #4 /home/wokadmin/monstrofun.ch/wp-content/plugins/sitepress-multilingual-cms in /home/wokadmin/monstrofun.ch/wp-content/plugins/sitepress-multilingual-cms/classes/xml-config/class-wpml-xml-config-validate.php on line 67
Perhaps you should contact your hosting company and ask for that as this involves settings that you might not have access and definitely requires some background in system administration in order to be done successfully and without an issue.