Kaltura_Client_Exception thrown

Invalid KS "ZDU1NjQzNjdhNmRhZWFkMWYxMTAyNTQ0YWM2MDU5YzgzZDg1M2Y4MXwxMDE7OzE0NzU0NDE2Mjk7MjsxNDc1MzU1MjI5LjExMTk7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"