Kaltura_Client_Exception thrown

Invalid KS "MzFhYjI5MGU5NmRmNmE1N2VhNWZmNzdhNGE3NGMwZWFlZGUxMTc4M3wxMDE7OzE0NzUwODQxNzQ7MjsxNDc0OTk3Nzc0LjA1MjI7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"