Kaltura_Client_Exception thrown

Invalid KS "MWYxNzczNzk4MGMzM2YwNjViN2E3NWEyNzE5NGM3MzQ5MDVlMmMwZnwxMDE7OzE1MDA3MjAzNTI7MjsxNTAwNjMzOTUyLjY2OTQ7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"