The most likely cause is that the onionsite is offline. Contact the onionsite administrator.
Details: 0xF0 — The requested onion service descriptor can't be found on the hashring and therefore the service is not reachable by the client.
@Null, the Tor service is playing up again (different issue from last week).
It seems to allow loading some stuff.. threads, member pages, etc, just fine. But then the various JS and images the pages need to display aren't loading, you can see the browser making requests for them, but.they just time out.
EDIT: As of an hour after this post, things seem to be working fine.