Over the last few weeks I have noticed a few times (even with MR) that I would get a pop up saying safari cannot identify the website server. The certificate is invalid. Happens on well known sites, I don't visit any odd obscure ones. Then yesterday it happened when I was trying to visit another popular automobile site I'm always on. This was on my iPhone at the time. Doing a little bit of research I guess it is somewhat common and there are a few tricks like resetting date and time which didn't work for me. Anyone ever experience this issue? Some folks can't even go onto YouTube or Facebook which I don't use. Others say to run keychain first aid but I couldn't find that option running on 10.12? It's getting a bit frustrating now. One site I visit often I cannot visit any longer on my home wifi only when I switch my iPhone over to LTE. Looking for any advice is appreciated ! Thanks!