Same here, played several times a day for 2 years until 12pm my time today - error says certificate has expired but gives no options to work around it, i know my friends are still accessing the site but i can't neither in Firefox nor Chrome. Please help ASAP!

Someone didn't renew their certificate? (See screen shot)

The reason you can't add an exception to continue using the old certificate is that the game page is inside a frame on Facebook. To add an exception, right-click the error page area > This Frame > Open in a new tab. Then you have the full set of tools available.

In the Add Exception dialog, I suggest unchecking the box to create a permanent exception (it's on the lower left corner). Likely they'll get a new certificate in a few days, so a temporary exception would be a better idea.

omg jscher2000 , i went in to try your suggestion and the game finally loaded without me altering anything! You must have magic MoJo :-)

They got the new cert loaded now. I bet someone over there got quite an earful about letting it expire!