I'm running Kubuntu 13.10 and KDE on top of Openbox. A few days after upgrading to 13.10 and after a regular software update, all the applications normally listed in "Applications" in the KDE launcher ("Start" button) are no longer listed. Additionally all file associations are gone (like what application should be use when opening pdfs) and the dialog box for file associations (when run from Dolphin) do not show any options.
This has been going on for days. At one point it started working but I have no idea why.
I tried running
kbuildsyscocoa4 --nonincremental and it seemed to run but it did not fix the situation. I removed my .kde directory (moved it) but that didn't help.
All the other users on my system have the same problem. Any new user I create has the same problem.
Gnome and Cinnamon are unable to fully load. Unity does but I don't want to use it (plus it has some issues). LXDE appears to be working fine and its applications menu is fine.
I have more issues that have cropped up since the upgrade but this is the worst.