Kaltura_Client_Exception thrown

Invalid KS "MmVlZjg5OThmY2QwMmEzZDVjZWJjYmUxYTM2NWNjODI4MDQ5MTRlZnwxMDE7OzE0OTA0MTUzNzA7MjsxNDkwMzI4OTcwLjA0NzY7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"