Okay, I'm onto something.
I had previously set the IIS_IUSRS account to 'full control' (above) and continued to get the error.
In an effort to narrow the problem domain, I set the permissions to 'Everyone' full control and that worked (Yippi).
So I need to go back to the drawing board and figure out what is the correct account to allow permissions.
I ran UBB for many years on Windows, going back to 2004. I seem to remember there being more IIS_user type permissions, so that's what I'm going to look into. (There is only one in the list now, but I may need to add that user.)
Anyway, thank you guys for the support thus far.
