Bingo! Thank you very much.
Indeed, the error occurs every time I load MS Edge.
I tried disabling the Microsoft Account Signin Assistant service as suggested by others, which does indeed prevent the error from occurring -- but it also prevents Edge from signing into my MS account and thus prevents it from syncing.
I was worried that disabling the service would prevent OneDrive from signing in and syncing, since I rely heavily on OneDrive. But OneDrive works just fine with the service disabled. Just MS Edge in my case (from what I've seen so far). Of course other apps as reported by other users.
I wonder if this is related to me signing into Windows with a local account rather than a MS Account. Microsoft clearly hates that, judging by the lengths to which they go to prevent me from doing it.
Not quite ready to dump Edge yet, although I could go back to Chrome if I have to. I will give it a little time to see if Microsoft provides a fix by the September patch. Now that they seemingly pushed the bug out to all their Win10 users (as opposed to just Win11 users) one can hope it gets on their radar.