You'll need to downgrade Fallout 4's next-gen version to play that massive Fallout: London mod
Next-gen update "isn't stable enough".
By now, you've probably heard of massive Fallout 4 mod Fallout: London, given the struggles it's faced in the run-up to release. There's one last hurdle for players to overcome, however, with developer Team Folon having now confirmed it'll be necessary to downgrade Fallout 4's next-gen version to play it - a process thankfully being handled by its accompanying installer.
Fallout 4's long-promised next-gen update finally launched in April, but its arrival caused some major headaches for the Fallout: London team. The mod was originally due to launch on 23rd April, but it was delayed after Bethesda announced Fallout 4's next-gen update would arrive two days later - Team Folon admitting it was concerned about potential "complications". And with good reason, it turns out; Team Folon has now confirmed a downgrade from the next-gen version of Fallout 4 will be absolutely necessary to run Fallout: London.
A downgrader was briefly mentioned in a statement the developer shared over the weekend, but its inclusion wasn't really detailed at the time. However, in a follow-up message on Fallout: London's Discord (via Ars Technica), project lead Dean Carter explained, "At the 11th hour we've discovered that the next-gen [version of Fallout 4], even after updates, isn't stable enough and thus we are now going out on the old version - thus the need for a downgrader."
Carter added that Bethesda's continuing updates to Fallout 4's next-gen release hasn't helped the London mod's progress at all. "It's been an utter frustration and every setback requires the testing process to restart," he explained. "Which is why we've decided to go with the downgrader route and when the 'next-gen' is sorted, update it for that."
Fallout: London will release via GOG (its massive size meant it was too large to host on Nexus Mods), and it's currently going through the company's quality-assurance checks ahead of its arrival. There's no release date for the mod just yet, but a post over the weekend claimed "the end is in sight", with the team seemingly just waiting for GOG to finish its work at this point. "Once they've completed the process of double-checking that Fallout: London and its installer work on all supported machines," it wrote, "we should be good to go."