Kaltura_Client_Exception thrown

Invalid KS "MzM2MzRmOWExMmMxZWViZjE5ZWU1NWFkNGU4ZTNlNmNlNDA0MDBiYnwxMDE7OzE0OTMxNjk2NDI7MjsxNDkzMDgzMjQyLjc2ODE7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"