Kaltura_Client_Exception thrown

Invalid KS "NzNlZjM2MTI4NWIyOWQ2YmUwNWIzZjJhOTQ2ZjZlZmI5ZTY0NDYwN3wxMDE7OzE0NzUwNTkzMjc7MjsxNDc0OTcyOTI3LjcxNDM7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"