In Ubuntu 16.04, trying to update software. Getting error message Failed to Download Repository Information
. My internet connection is OK. Changed the server twice and still get the same message. Here is a copy of the detail from the message:
W:The repository 'http://ppa.launchpad.net/jfi/psensor-unstable/ubuntu xenial Release' does not have a Release file.,
W:Data from such a repository can't be authenticated and is therefore potentially dangerous to use.,
W:See apt-secure(8) manpage for repository creation and user configuration details.,
E:Failed to fetch http://ppa.launchpad.net/jfi/psensor-unstable/ubuntu/dists/xenial/main/binary-amd64/Packages 404 Not Found,
E:Some index files failed to download. They have been ignored, or old ones used instead."