Macbook Air 2012 Mail works fine on WiFi or ethernet, but browsers cannot connect. What could be the possible cause? The internet system prefs pane says it is connected and has an assigned IP address. Running 10.9.2 and Safari was working fine a few days ago, suddenly stopped. Tried a reset in Safari, no change. Google Chrome doesn't work either, got me stumped. It is not my machine, but owned by a good friend, who is not very tech minded. Any ideas appreciated. Resolved; deleting the files noted below in the HD/Library/Preferences/SystemConfig folder immediately cleared the problem. I also ran Disk Warrior on the target SSD (lots of red ink!) and Onyx to clear off some of the built up junk. Pretty speedy laptop now, 11" MacBook Air!