Kaltura_Client_Exception thrown

Invalid KS "MzgwYWJjMDNhZDgwMmJhOGZlOGU4ODViZDY0ZGI0Mjc0ZmExYTU3MHwxMDE7OzE0OTA2NDk5Nzg7MjsxNDkwNTYzNTc4LjI2MzU7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"