At 12:00 AM Greenwich Mean Time the site's security certificate expired. Your browser probably displayed an alarming-looking message because of this, and probably made it difficult to get to the site.
I believe this error to be resolved now. Also, there was no real risk associated with this issue.
Some details: The certificate that expired has two purposes. First, it's used to encrypt your communications with the site. Second, it's used to "validate that the person you're communicating with is who he claims to be." I've never quite wrapped my head around what the nerds-in-power think that means (who exactly do I "claim to be?"), but in any case this second part requires communicating with said nerds annually, paying a small fee, and putting some files they give me on the server.
I will strive for a more seamless renewal process next year.
