W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/main/source/Sources 404 Not Found [IP: 18.104.22.168 80] ....
14.10 is now EOL. See this
Consider upgrading to 15.10 instead of trying to keep going after EOL.
One might suggest that non LTS releases have a ridiculously short lifetime (9 months feels short to me), but it's a tradeoff. You get the latest/greatest, but have to upgrade more often :)