Kaltura_Client_Exception thrown

Invalid KS "ZWEwMDVhYTViNWZiYTEyOTI3OWYzYTRkODUwY2ViYTBhMTNjYjZkN3wxMDE7OzE0NzUwMDUyMTQ7MjsxNDc0OTE4ODE0LjE0ODc7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"