Kaltura_Client_Exception thrown

Invalid KS "MzhiM2M1OTIxYjZjMDk0OTRiOTg5MzUyYmRjMjE5MGE4MTg0NWY1OHwxMDE7OzE0OTM2MDI2ODc7MjsxNDkzNTE2Mjg3LjQ3NjU7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"