Why won't my MAC connect to MOL?

I have been trying to connect to Marine Online, i have been able to get in to this site before from this computer and now it is saying that i don't have the proper certs or something. I have been able to just say continue on against their suggestions but now it won't even go to that page. there was a similar question asked last year, it received a response and i tried the solutions that it was given to no success.