Kaltura_Client_Exception thrown

Invalid KS "MjhkMzEyMzRhMWE1MWVmZmJlMjJlNzFhNDRkZGQzYjA3YjdkZDk3ZnwxMDE7OzE0OTMzNTEwOTY7MjsxNDkzMjY0Njk2LjY0NjQ7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"