Last night I upgraded to NTA 4.2.3.
Today while reviewing the Message Center's records I found this error recorded:

I clicked on the Help link, expecting to find a cool and intuitive explanation of what I should do. Instead, I came to this page:

This Discussion is simply a kind and gentle reminder to update the NTA links so they point to valid pages, or to update the pages so there's something present to go to when clicking on the Help link from within the Message Center.