dtdns.net closed for business last June. There was a thread about this back at that time.
elgur.crabdance.net:7300 or elgur.dyndns24.ch:7300 are the 2 URLs that are supported.
(DNS24 is a Swiss company and so will be, like many things Swiss, reliable and trustworthy.)
Thanks, Andy, my wife and I were away for the winter and just now back home getting things organized. I didn’t think to search the Reflector but will make the changes in my software.