All previous links in this thread come up "Server Not Found" using Firefox 50.1.0 on 2 Windows 10 64 bit computers running the 64 bit version of Firefox.
If I type mppusers.com in the browser address bar I get the web site and if I copy the web address as listed on the main page for bookmarking and paste it into the address bar of a new tab I get the website.
http://mppusers.co.uk as posted on the web site.
http://mppusers.co.uk/wordpress/ as shown in the address bar once the website comes up.
Logged out, cleared browser catch, closed browser, reopened the browser, navigated to this thread, tried both links I posted and they work, logged in and made this edit. Correction: post 8 works if highlighted then opened.