I'm relatively new to Ubuntu 16.04, and everything has been going fine until my OS threw this error today.
Below is the source code from /etc/apt/sources.list for line 54:
deb http://archive.canonical.com/ partner
I have tried appending ubuntu after the / and before partner, but this does not seem to work.
Any ideas what else to try? I can't run sudo apt-get update until this is fixed.