I am re-purposing an old laptop. I installed 11.10 on it and then immediately upgraded to 12.04. (I could not directly install 12.04 as my system does not support PAE.)
When my system was (briefly) 11.10, the desktop appeared as expected. However, after the upgrade to 12.04, the icons in the launcher area are invisible. If I hover over the spot where the icon should be the little popup window showing the tool's name appears, and I can click to invoke the tool. I just cannot see the icons.
The icons do appear as expected in other contexts, for example in the Home folder and in Dash Home.
My theme is "Ambiance (default)"
I do not have a ~/.icons folder.
This is the top level contents of /usr/share/icons:
default DMZ-Black DMZ-White gnome handhelds hicolor HighContrast HighContrastInverse Humanity Humanity-Dark locolor LoginIcons LowContrast redglass ubuntu-mono-dark ubuntu-mono-light unity-icon-theme whiteglass
(Sorry for the poor formatting, can't get it to show in list.)
I suspect that the launcher isn't looking for the icons in the right place, but I don't know how to confirm that, or how to correct.
This is my first foray into Linux, although I used to use Unix a few decades ago. This doesn't look much like my old Sun workstation, though!
Does anyone have any suggestions or insights for me? Thanks.