A vpn will get rid of that and any other blocks that the uk isps now have. The block rarbg, piratebay, extratorrent, Mov**4k to name but a few, or if the app allows it then you can find a version of the url that is not blocked like.
Been a few addons etc that i have had to change the links to get working and that included downloading, ammending the source code then copying it over the existing addon.
To be fair, most authors on here are most helpful and will go out their way to help you, so ask in the correct sub forum. Some people cannot always answer a question as i have found out lol. (Look a few posts below yours at mine 55 views and not one bit of help)
Any other help, then ask, but i personally don't see the need for one that often and i use the free web version of ZENMATE which is an addon for firefox or chrome and is a Web Browsing VPN.