Kaltura_Client_Exception thrown

Invalid KS "MWMyYzI2OTJiODU4ZmQ2YTlkY2QzNGMyODkwYzY5MTBkYTUzMTBhYnwxMDE7OzE0OTMwMTE3Nzk7MjsxNDkyOTI1Mzc5Ljg0OTM7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"