I already worked out that the words "(old version)" indicated that I should remove the totally newly installed validator. So I did it, and it completely killed Dreamweaver. After another wasted half hour I fixed that problem, re ran the setup, installed the extension again and ran "create security pages."
Inspection of the code generated showed multiple identical server behaviours which caused a loop in the redirect script.
So I deleted the additional server behaviours, and that got rid of the loop.
It now takes the input and always redirects the login page to the "wrong password or email address page."
And there are 4 more pages to sort.
Not a happy bunny, having expected to have a login system up and running in an hour at the most.
How about a set of example settings for a the four pages, that just get the basics working?
At least then one would have some code that works for comparison and no doubt it would save a lot of work for the forum?