Could it be that the extension is not installed at all? It’s not on my utopic setup (upgraded from trusty, itself upgraded from saucy, it might be that at some point I manually uninstalled it).
$ apt-cache policy xul-ext-unity xul-ext-unity: Installed: (none) Candidate: 3.0.0+14.04.20140416-0ubuntu1
Could it be that the extension is not installed at all? It’s not on my utopic setup (upgraded from trusty, itself upgraded from saucy, it might be that at some point I manually uninstalled it).
$ apt-cache policy xul-ext-unity 04.20140416- 0ubuntu1
xul-ext-unity:
Installed: (none)
Candidate: 3.0.0+14.