Comment 4 for bug 1403103

This has been present since 12th December (day I started testing on vivid) on a post-installation of vivid which I'm running off everyday:

..snip..
Get:17 http://security.ubuntu.com vivid-security/multiverse amd64 Packages [14 B]
Err http://extras.ubuntu.com vivid/main Sources
  404 Not Found
Get:18 http://za.archive.ubuntu.com vivid/restricted Sources [5,872 B]
Get:19 http://security.ubuntu.com vivid-security/main i386 Packages [14 B]
Get:20 http://za.archive.ubuntu.com vivid/universe Sources [6,991 kB]
Err http://extras.ubuntu.com vivid/main amd64 Packages
  404 Not Found
Get:21 http://security.ubuntu.com vivid-security/restricted i386 Packages [14 B]
Err http://extras.ubuntu.com vivid/main i386 Packages
  404 Not Found
Ign http://extras.ubuntu.com vivid/main Translation-en_GB
Get:22 http://security.ubuntu.com vivid-security/universe i386 Packages [14 B]
Ign http://extras.ubuntu.com vivid/main Translation-en
..snip..
Fetched 28.7 MB in 1min 1s (464 kB/s)
W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/vivid/main/source/Sources 404 Not Found

W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/vivid/main/binary-amd64/Packages 404 Not Found

W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/vivid/main/binary-i386/Packages 404 Not Found

E: Some index files failed to download. They have been ignored, or old ones used instead.