Comment 5 for bug 1000506

I just upgraded to KDE 4.9.1. Now Plasma crashes almost every time I launch any application. Sometimes it seems to crash while starting, so KCrash fails to relaunch it, and I almost get stuck with no UI, unless I can find another way to launch it.

plasma-desktop:
  Installed: 4:4.9.1-0ubuntu1~ubuntu12.04.1~ppa2
  Candidate: 4:4.9.1-0ubuntu1~ubuntu12.04.1~ppa2
  Version table:
 *** 4:4.9.1-0ubuntu1~ubuntu12.04.1~ppa2 0
        500 http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu/ precise/main amd64 Packages
        100 /var/lib/dpkg/status
     4:4.8.5-0ubuntu0.1~ppa3 0
        500 http://ppa.launchpad.net/kubuntu-ppa/ppa/ubuntu/ precise/main amd64 Packages
     4:4.8.4a-0ubuntu0.1 0
        500 http://us.archive.ubuntu.com/ubuntu/ precise-updates/main amd64 Packages
     4:4.8.2a-0ubuntu4 0
        500 http://us.archive.ubuntu.com/ubuntu/ precise/main amd64 Packages