Kaltura_Client_Exception thrown

Invalid KS "MzZlNmY1MzUwMDY4MGFkZDYzNDE3YzBiZWRmYzg3MjYyNWQzZTBlYXwxMDE7OzE0OTgzMjY2MjY7MjsxNDk4MjQwMjI2LjYxODk7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"