Kaltura_Client_Exception thrown

Invalid KS "NmU1NDk0ZGM4OWEwMGQ5NDYxMWMzYjg2YzYyZDhlYjg1MWViMzI4MXwxMDE7OzE0OTMwNzgxMzc7MjsxNDkyOTkxNzM3LjM1OTk7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"