If rebooting the computer and game client doesn't resolve this, try making sure your web browser(s) are up to date. If that still doesn't resolve it, get in touch with Technical Support here: https://help.standingstonegames.com/...s/requests/new
The web site navigational changes were simply consolidation and changing a few URL directs, so had no connection to the game client.
Thanks for quick reply - I couldn't see how the navigation change would have affected the store and help screen in-game but it seemed worth mentioning the timing just in case.