Fatal error: method_exists(): The script tried to execute a method or access a property of an incomplete object. Please ensure that the class definition &quot;unknown&quot; of the object you are trying to operate on was loaded _before_ unserialize() gets called or provide an autoloader to load the class definition in /htdocs/wp-content/plugins/sitepress-multilingual-cms/classes/language-switcher/class-wpml-ls-templates.php on line 304