E: Failed to fetch http://debian-packages.cargomedia.ch/dists/xenial/main/binary-amd64/Packages 403 Forbidden [IP: 112.124.140.210 80]
E: Some index files failed to download. They have been ignored, or old ones used instead.
At the moment only Ubuntu vivid (and Debian jessie) is supported. Some packages even only in one codename. We will not provide xenial packages anytime soon.
i try to use this in xenial.
got this error