When I run apt-get update, is it supposed to have YOUR_UBUNTU_VERSION_HERE?

Question

I'm getting errors like

Err http://ppa.launchpad.net YOUR_UBUNTU_VERSION_HERE/main Sources             
  404  Not Found

Is it actually supposed to say YOUR_UBUNTU_VERSION_HERE, or is there some kind of an error that keeps it from writing my Ubuntu version?

Answer 1

A correct line in /etc/apt/sources.list looks like this:

deb http://ppa.launchpad.net xenial/ main

or

deb https://cran.r-project.org/bin/linux/ubuntu xenial/

Note the / directly after the version ("xenial"), and the space after the /.