Kaltura_Client_Exception thrown

Invalid KS "MzkxY2E4ZWM4N2EwN2I1YTdlYzg1ZDZlM2MyZDhhNjk3N2FlNmYxYnwxMDE7OzE0OTA2OTgzNjE7MjsxNDkwNjExOTYxLjA2Mjg7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"