I am unable to access using the IP number too, just as I suspected.
The message is provided by either the forum software/server or may be the host server that is hosting it?
Did a ping test :
PING 199.231.58.82 (199.231.58.82) 56(84) bytes of data.
64 bytes from 199.231.58.82: icmp_req=1 ttl=51 time=373 ms
64 bytes from 199.231.58.82: icmp_req=2 ttl=51 time=396 ms
64 bytes from 199.231.58.82: icmp_req=3 ttl=51 time=419 ms
64 bytes from 199.231.58.82: icmp_req=4 ttl=51 time=442 ms
64 bytes from 199.231.58.82: icmp_req=5 ttl=51 time=465 ms
64 bytes from 199.231.58.82: icmp_req=6 ttl=51 time=386 ms
^C
--- 199.231.58.82 ping statistics ---
6 packets transmitted, 6 received, 0% packet loss, time 5004ms
rtt min/avg/max/mdev = 373.349/414.149/465.697/32.264 ms