If you are getting error code 16, just use "save as" for some reason using either "save" or "save and quit" both seem to give that error but "save as" does not(at least on my game).
I had trouble getting any mods working when i was using windows xp service pack 3. when I uninstalled that and went back to service pack 2 they worked. This may have been a fluke or maybe just a windows ghost bug that just happens. but thought I would mention it just cause it may help.