Comment 11 for bug 329522

It seems that KDE cache doesn't get updated when it should.

As a workaround, if you experience "findServiceByDesktopPath: fileshare.desktop not found" error when clicking on "Configure file sharing" (kdesudo kcmshell4 fileshare), try removing contents of /var/tmp/kdecache-root. It'll be updated automatically and the file sharing dialog should start without errors.