Okay, I checked my prefix; it's still 4502, and I doubt that it's used by anyone else since I reserved it on the Alcugs Wiki and my Age worked with it before.
I also checked on Pages 0, -1, and -2, and all appears happy.
Layer two--so that's where the the link-in point is placed! I was wondering where it was...Well now I know.
And it appears that the original link-in point I had was not deleted, so I have had two link-in points since then. I just deleted one of them, tried Uru again, and the same thing happens in which I crash to desktop with no error message. The link-in point remaining appears to be in a valid location, hovering in the air above the grid. I have flymode downloaded in zip mode, but I don't remember ever unzipping and installing it, and it appears from the files which I see after searching my hard drive that I never did install it. Well, I guess I'll try uninstalling the ULM next. Thanks again for your help, Andy; and you don't sound condescending at all--I LIKE detailed explanations!