Apparently I introduced this error when I made
these changes on November 30, which (as of the time of this update) was when the "Last Updated" column on the Member Collections page stopped getting new data. There is one date after that, but that's from a new member whose date was updated when he was added, rather than when his collection was updated, so it was triggered by a different code block which didn't contain the above error.
Try it now.
Sandy