Hi, I've been having this problem where almost every website I go to (excluding Facebook and gmail) comes up with a 400 error message. This happens in both Safari and Chrome, even after I have cleared my browsing history, cookies, and cache, and scanned for malware and deleted it. Im using a MacBook Air running OS 10.10.5 (there is an update available but I can't install it because I get a 400 error message when I try!!!) I'm at a loss for what to do, can anybody help?