The first symptom of an issue was the certificate errors message in Internet Explorer. So I investigated and looked at the source of the page and found this line:
Since that comes from a non-Geni site, I figured that was the cause. Sure enough, when I visited that address in my browser, I was presented with the more blatant error page:
Continuing onward, I was able to see why Internet Explorer was complaining:
Sure, enough, when you look at the certificate, you see that it is for www.facebook.com and not www.connect.facebook.com. I proceeded to notify Geni with a workaround and notify Facebook of the problem.
Hopefully, Facebook will fix the issue and Geni will be able to workaround it in the meantime.