I had the same issue after upgrading from Kubuntu 15.10 to 16.04. The workaround mentioned in the comment #7 worked for me.
-- You received this bug notification because you are a member of Kubuntu Bugs, which is subscribed to kubuntu-meta in Ubuntu. https://bugs.launchpad.net/bugs/1450068 Title: Icons missing in Plasma/KDE after upgrade to Ubuntu 15.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/kubuntu-meta/+bug/1450068/+subscriptions -- kubuntu-bugs mailing list kubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/kubuntu-bugs