Kaltura_Client_Exception thrown

Invalid KS "YWNhMjNhMThlMTAyMGYyOTAxMGQzYTU1Njk4NWNlMTE5ZDE0ZDQ2ZXwxMDE7OzE0OTg2MzQ5Mjk7MjsxNDk4NTQ4NTI5LjYyNTc7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"