When Applescript tells me this:
0:2570: execution error: iTunes got an error: An error of type -116 has occurred. (-116)
It apparently really wants to tell me that it has encountered a track in its library that no longer exists on any filesystem.
Thanks, that was so obvious. NOT! Oh, and good luck trying to search for -116 with Google, since it interprets that as a request to exclude results that contain the 116 search term, last I checked. 
I think you can put the ‘-’ in quotes; “-116″ instead of -116 or -”116″.
That doesn’t seem to work, it turns up pages with 116 in it, the ‘-’ seems to be ignored then.
Using “An error of type” “-116″ “has occurred” itunes actually turns up two results, but “An error of type 116 has occurred” itunes or “An error of type -116 has occurred” itunes gives me nothing at all.
Fun.
Huh. I could swear they supported that, but it acts like “-” isn’t indexed. (which I think is true of most symbols).
LOL. I just tried the search in Google, and it brought me back to this page.
Yay, I’m famous!