I'm not sure what happened, but I reinstalled LV 8.6.1 and tried the patch again - backing up the "patched" files first . The patch installed just fine this time. I have been having some licensing issues since I upgraded to 8.6 last year and I think I got that resolved using a different license number when reinstalling it this morning. This little adventure helped me resolve an issue I've been fighting for over a year. And no loss of productivity, either since most of my Thursday mornings are spent in meetings.