Kaltura_Client_Exception thrown

Invalid KS "NWJkMWMyNDcyZmZmZWIwNGU5Nzg2MTBjOTRkMjY1OWIzNjU3ZDQ4YXwxMDE7OzE0OTg1NDgxMTY7MjsxNDk4NDYxNzE2Ljg3OTQ7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"