The Logitech Media Server (Formerly Squeezebox Server, SqueezeCenter) is a bit of a pain to get working in the latest Ubuntu. Logitech's support for the entire line seems to be waning, and they have even stopped making some of the better units (like the SqueezeBox 2) and are possibly just selling out the rest of the line.
I never did understand their approach to marketing the products. I always felt like it was a much bigger and better line than most people thought, and their marketing message was never very clear.
But, I still run multiple Squeezebox devices, and love the line despite all that. Unfortunately it makes it a bit of a trick to get it running on the latest Ubuntu because the Logitech guys are behind on their use of certain packages that no longer exist.
First, an out-of-box install of the Logitech Media Server (LMS) requires the following additional packages be installed:
sudo apt-get install libjson-xs-perl libev-perl libyaml-libyaml-perl
You would think since they provide an Ubuntu package that it would automatically depend on those but it doesn't. The server will just refuse to start if you are missing them.
Lastly, you need a package that doesn't exist in Ubuntu anymore. If you check out the Ubuntu bug report on it, LMS isn't the only project still trying to use the old Perl module. Someone has kindly provided a package that will work for 12.04 however that fixes the problem.
Download this package which is also linked inside the above bug report. After it's download just double-click it and let the package manager install it. I did not put that package together and cannot really vouch for it, but I'm using it myself.
With those additional packages, your LMS should start. It's possible my particular system already had another prerequisite installed, but those are what I needed to add to get it to work.