Kaltura_Client_Exception thrown

Invalid KS "MWQzYWQyY2RiOGNmZjdlNjA2MjJmYzYxOTc1NTRlMGY4MjA0ZTA2NHwxMDE7OzE1MDEwNDQ2MDA7MjsxNTAwOTU4MjAwLjI3OTE7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"