Kaltura_Client_Exception thrown

Invalid KS "MDBkNGVlZTY0YTRiNGI4MDY4OTFlY2Q0YmQxMjMyNDhjOGEyZWY0NnwxMDE7OzE1MDA5NTc5Njc7MjsxNTAwODcxNTY3LjY4Njc7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"