I'm using Kubuntu 14.04. I lost my desktop and got error
unable to launch "/usr/bin/startkde" X sesssion - "/usr/bin/startkde" not found; falling back to default session. I found a possible fix in a post and I followed the instruction by entering the terminal using
sudo apt-get update sudo apt-get install -f sudo apt-get dist-upgrade sudo apt-get install kubuntu-desktop
The last command results unmet dependencies problem and I got stuck.
The result of
apt-cache policy kubuntu-desktop kde-workspace plasma-desktop plasma-netbook looks like
I encountered the similar problem before that I could successfully install the desktop, but I think this case is little different from it.