Run Fallout: London from its personal sport card in GOG GALAXY. Don’t use the Fallout 4 sport card. If you happen to're not utilizing GOG GALAXY, ensure you're utilizing …
Source : https://www.gog.com/forum/fallout_london/fallout_london_remember_about_the_right_way_to_launch_it
Fallout: London – remember about the right way to launch it, page 1 – Forum – GOG.com
