Thanks, Walt. Running the help file directly from disk works flawlessly. I just created a shortcut to it on my desktop, so that resolves my issue.
To answer your other two suggestions...
I am running Windows 7. (Old, I know, but it is listed as being supported by Affinity Photo. I do plan to upgrade to Windows 10 here within about a month, so that will probably resolves this, if only because of the re-install.)
Clicking "Yes" on the script-error dialogs (there were five of them, in rapid succession) did bring up the help-window, but content was missing and the buttons (like "search") didn't work.
I'm all set for now. Thanks much for your help.