Kaltura_Client_Exception thrown

Invalid KS "M2FkNDYwZDBhNTBlYmQ1ZDhhMzI0YTAzNDIyZWJhNzIwZTYwZjM5ZHwxMDE7OzE0OTg0Njg3NzU7MjsxNDk4MzgyMzc1LjgzNzU7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"