Kaltura_Client_Exception thrown

Invalid KS "MTI4ZTNhMTZiNzI3NGU3YTcyODI1MmUyM2U1YjM1Y2VmYTQ1Y2FkNnwxMDE7OzE0OTA5OTQxNjk7MjsxNDkwOTA3NzY5LjI4ODQ7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"