apparently it is not working because they have blocked some IP as they are under attack, i'm in italy and my PC doesn't work but from my phone it's working fine. Try with a VPN service. Here the official statement:
News
2017-09-08 20:46 - We have to block IP-ranges
We are still under attack and this time it is the login page that we can't disable. Instead we have blocked some IP-ranges where most of the attacks are coming from.
2017-09-08 20:31 - Registration page disabled for the weekend
We have disabled registration page now to free up resources since we are under constant attack. During next week we will hopefully be able to release a new registration function that will be resistant against this type of attack.
OK. That explains it. Wonder if it would be possible to have IPs whitelisted.