The premium membership is currently closed to new members
If you have already signed up, the membership area is still active and works.
However, for technical reasons, the new member sign up part of the membership system is not working. I hope to have this fixed in September 2017, and re-open the membership then.
If you have any questions, please send me an email at email@example.com. It might be a few days before I can reply because I am currently away on holiday for most of August 2017 visiting family. I will be up to speed again in September.