Kaltura_Client_Exception thrown

Invalid KS "MWRiZDZiYzk2OTE4MDE5NmMzODExMGFhMTVhMWU0N2E3MGI0MzRmZnwxMDE7OzE0OTA2OTczNzk7MjsxNDkwNjEwOTc5LjQxMTE7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"