1. Check your sources.list and files underneath sources.list.d
Originally Posted by Langstracht
==> All those entries should point to *.ubuntu.com servers
==> comment out (= place a "#" in front of it) any other strange entries ...
... or simply come here and ask. The goal here is to remove anything
that Automatix might have added.
2. Underneath /etc/apt/sources.list.d you might have *.list files. Take a look at those. Same as above: if anything they should point to *.ubuntu.com or *.ppa.launchpad.net servers ... Be super-duper suspicious of anything that points anywhere else. Stuff you know for 100% sure _you_ added is OK ... but please remove anything that Automatix might have added.
3. Once this is done:
4. Resolving conflicting packages is ugly. I'd suggest to remove "mozilla-dev" (probably installed via Automatix?) because usually it's not so essential (I for example have tons of stuff but not that package ... so it can't be that important I guess?
sudo apt-get clean
sudo apt-get update
Once "mozilla-dev" is gone the package manager should resolve the remaining issues by itself.
sudo apt-get remove mozilla-dev
If it doesn't ... please give me the error messages you get after removing "mozilla-dev", OK?