I was upgrading my ubuntu 12.10 to 13.04, using following command:
sudo do-release-upgrade
everything is OK until I get following error message :
Could not download the upgrades
The upgrade has aborted. Please check your Internet connection or
installation media and try again. All files downloaded so far have
been kept.
Failed to fetch
http://archive.ubuntu.com/ubuntu/pool/main/a/account-plugins/account-plugin-facebook_0.10bzr13.03.26-0ubuntu1.1_amd64.deb
Size mismatch
Failed to fetch
http://archive.ubuntu.com/ubuntu/pool/main/f/friends/friends-facebook_0.1.3daily13.04.17.1~13.04-0ubuntu1_all.deb
Size mismatch
Restoring original system state
Aborting
Reading package lists... Done
Building dependency tree
Reading state information... Done
Building data structures... Done
what should I do for this?