Looks like I'm getting old. I didn't see the connection.
And yes, I'm using FireFox.
Anyway, ran it, rebooted - no change. Icons still empty and entries grayed out.
Maybe I should point out that the icons are from different programs, not only Office. I saw in one of the posts in the Google-link that the solution was to re-install Office as it must have disappeared, :-)))))))
And the poor guy clearly stated that the icon issue also applied to Adobe's Reader. People don't read.
I just noticed something else: the shortcut arrows are back. So I started Tweak and it can't do anything. After a while it's "Not Responding" and I can close it, but nothing changes on my desktop. What has happened here?
OK, back to the drawing board.