Thanks for that, Quark. I'm trying it now. It definitely removed the error and my wallet balance looks OK, but it's starting one of those loooooong sync cycles so I'm not yet sure everything is OK.

Normally I wouldn't take that kind of advice from a newbie poster (nothing personal), but it looked so reasonable I had to try it. My memories of SQL are decades old and not reliable. Nice to see it looking so current, and good to see someone who knows how to use it.