Delete Keyword Tag Failed

When trying to delete old "places" keyword tags after have assigned a Place to the pictures, I get a "Delete Keyword Tag" advisory.

I can eventually clear it, but the tag does not delete, until I close the program, open the program, and delete the tag again.

Sometimes it works OK, but about one half of the deletes provide this error.

Using PSE 14 on windows 10.

Any thoughts??