I tried to register and it shows the 'error' message.
It shows that there are 4,798 rolls since morning. Reading the old posts, support is no longer active and even the owner for this thread.
I believe the owner is still active monitoring the site. As a proof, the domain was expired some time ago and it has been just renewed. Means that the owner is still working to make this site alive but indeed he seems to be inactive in this thread to answer or at least to give an update on what is going on with site regularly.
But the new registrations were disabled if you're going to try it. And the one that renewed the domain isn't the owner of kingdice but wetsuite.
Thanks for this info.