Now this is weird!

I fixed the permissions and used the VMFusion window and applications OK.  Also made a backup of files used on this occasion.  We then had a brief power failure 1 hr ago, and after power come back on, the Broken Pipe message reappeared.  I checked and there had been no additional installs since I checked this morning, in fact no upgrades or new installations on today's date.  I did note that TeamViewer tends to reinstall itself after a reboot so perhaps it is something to do with that, but I guess Norton also sets itself up in the background.

Over to you for other interpretations; for the moment  I will keep adjusting permissions via Terminal.  Too hard for me.