Kaltura_Client_Exception thrown

Invalid KS "OWFlYTY5ZmQ2YmJmNWZiY2VmMTRjYTgyZWUwM2E4ZGNjZTg0YjBkNnwxMDE7OzE0OTgzNTE1NTk7MjsxNDk4MjY1MTU5Ljc2MDU7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"