Map Freezes shortly after loading

I'm on day 50 of a game, and my map has suddenly started freezing. The map will load initially, but when I move SE from the starting point, the map will freeze. If i try to move the map will appear to move, but then will snap back to the last position. Also at this point most of my units disappear.

I've logged out and back in, switched browsers, and computers. The problem is not going away.

Thanks,

Kevin