When I'm trying to update my system (Linux Ubuntu 16.04 LTS) through
Software Updater, I receive the following error message:
Failed to download repository information Check your Internet connection.
First I thought it might be the server where it's trying to download the repositories, so I went to
Software Updater -> Settings -> Ubuntu Software and changed the
Download from selection from
Server for United States to
Other -> Select Best Server. As a result, my new server is http://www.nic.funet.fi/pub/mirrors/archive.ubuntu.com
When returning to the main window, I receive a following notification:
The information about available software is out-of-date To install software and updates from newly added or changed sources, you have to reload the information about available software. You need a working Internet connection to continue.
Now, after clicking the button
Reload, Software Updater starts to update the cache. However, this results into a failure with the following error message:
Failed to download repository information Check your Internet connection. Details W:Target Packages (Packages) is configured multiple times in /etc/apt/sources.list:53 and /etc/apt/sources.list:54, W:Target Translations (en) is configured multiple times in /etc/apt/sources.list:53 and /etc/apt/sources.list:54, W:The repository 'http://ppa.launchpad.net/landronimirc/clamtk/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/landronimirc/clamtk/ubuntu/dists/xenial/main/bina ry-amd64/Packages 404 Not Found, E:Some index files failed to download. They have been ignored, or old ones used instead.
So, it seems I am unable to update my system at the moment. Does any of the good people here on the forum know how to fix the problem?
Thanks in advance! :-)