Thanks so much for your help, guys,
Unfortunately for me, I am still a noob, so I didn't realize that there was a difference between a 'Product' and 'Plugin'. I had eliminated all of my products, but not all of the plugins. Most of them were taken out when I eliminated the products, but not all. I did manage to find the offending script in this case. It was a plugin I had installed when I was still in version 3.6.8 which is this particular mod:
https://vborg.vbsupport.ru/showthrea...fo+banned+user
It worked fine in 3.6.8, but apparently not in 3.7.1 and onward.
Anyway, eliminating that plugin resolved the problem and of course serves to point out this old mod's incompatiblilty with version 3.7.x
Thanks again for the help.