Some words up in front:
This is my Guide, with my collected experience (during the process) on how to install Fallout London with Mod Organizer 2
I will not explain Steam versions, rolling back FO4, installing F4SE, etc. this is not the aim of this guide
At this time Fallout London is absolutely working fine for me. Since this is the first time playing it, i did not come yet to the point -the train ride- where several people report that FO:LON crashes. but it addresses all the major hurdles i came by. (If somebody finds an repeatable solution on how to reliably fix this crash, i'll be happy to append it to this guide)

Let's start:

Pre-requirements:

- Mod Organizer 2 installed (from now on called MO2)
- some Basic knowledge on how to use MO2
- Fallout 4 GOTY 1.10.163 version installed and managed via MO2 (from now on called FO4)
- No HiRES Texturepack installed for FO4 <- This is very important
- F4SE 1.10.163 installed in FO4
- FO4 at least once started
- it doesn't matter, how many mods you've installed for FO4 as long as you've done it via MO2 (otherwise no warranty and help from me)

Fallout London (GOG) download
Open GOG Galaxy, my way is to not use GOG Galaxy INSTALL button, but click on Extra (left beside it) and download in the new picture the offline DRM version of Fallout London.

Preparing the FO:LON files
Once downloaded, change to the folder where GOG downloaded it to, double click on the setup file, in the popup, read and then tick the EULA tickbox then click on Options to be able to select, where to unpack the FO:LON installation files to. (in principle this just unpacks the files but doesn't install FO:LON), then click INSTALL. You need around 40GB of free disk space. This takes a while....

- When completed you can delete the downloaded FO:LON installation files again, to free up space.

Collecting the required files
- to be able to store the necessary files for a later installation, remove clutter and easier find them in the following MO2 implementation, prepare now a safe folder somewhere on a fast HDD or SSD to collect the required files for MO2 (must be also around 40GB free disk space), (Name it something like Fallout London or FOLON, whatever you like) (i will refer to it from now on as safe folder).

- Now change again to the directory, where the GOG's FO:LON Setup unpacked the FO:LON files to ! The folder should look like this (see picture: FOLON_Folder.jpg)

1. Rename the Data folder to something like Fallout London and copy the (now called) Fallout London folder to your previously created safe folder <- this takes a while (it's around 40GB)
2. open the _Config folder and copy the 2 ini files (Fallout4.ini & Fallout4Prefs.ini) also to your safe folder
3. copy the files WinHTTP.dll and xSE PluginPreloader.xml also into your safe folder

- ensure, that you have all the 4 files and the Fallout London folder in your safe folder !!!
- delete the FO:LON folder where GOG FO:LON setup unpacked the FO:LON files to, you don't need it anymore.
- You could, if you want, at this time also pack your safe folder with 7z, WinRAR, WinZip (whatever you like) and store the zipped file on a Backup drive, but leave the unpacked safe folder there ! (again this will take a while, since it's about 40GB (again) but then you have all necessary files for whenever you want to re-install FO:LON in the future with MO2)

Congratulations ! The first part is done, well done, let's continue

Inserting the folder and files from your safe Folder into MO2

Part 1:
The Fallout London folder (previously Data folder)
- start MO2
- create a new instance in MO2, point it to Fallout 4 and name it Fallout London (in principle you now have two FO4 instances, one called Fallout 4 (with all your mods), one called Fallout London, but the FOLON instance should be clean ! (see picture: fo4_clean_inst.jpg on how MO2 FO4 instance should look like)
- ensure that you are in the newly created Fallout London instance !
- Now click on the little folder icon in MO2s main window and choose Open Mod Folder (see picture: MO2_FOLON_folder.jpg) this opens MO2s Mod folder for Fallout London.
- copy the Fallout London folder from inside your safe folder into the now open MOD folder window from MO2 (again, this takes a while...cleanup will come later)
- when done, close the Mod folder window again.
- refresh MO2 and tick the now appeared Fallout London Mod on the left side.

Part 2:
The 2 .ini files (Fallout4.ini & FalloutPrefs4.ini)
- open -INI-Editor- (2nd picture from right (looks like puzzle pieces)) in MO2 (see picture: FOLON ini.jpg)
- replace the complete content of Fallout4.ini with the content of Fallout4.ini from your safe folder
- replace the complete content of FalloutPrefs4.ini with the content of FalloutPrefs4.ini from your safe folder
- save changes, close INI-Editor
- refresh MO2

Part 3:
The 2 xSE Mod files (xSE PluginPreloader.xml & WinHTTP.dll)
Now we need to get the xSE Plugin Preloader mod running (which was added to FO:LON with the last update to V1.02)
(This is the root cause, why you can't switch to female during the character creation of FO:LON) <- took me a while to find this one out ! ;-)
- Open a file explorer and navigate to your Fallout 4 installation directory and just copy the two files (xSE PluginPreloader.xml & WinHTTP.dll) into it. Not into Data !!! Into the root directory of Fallout 4 !!! (No worries it will not affect your normal FO4 installation, since you don't use them when running FO4.)

Part 3a: (last part, but a bit more tricky)
Adding the start option parameter in MO2 for F4SE to load xSEPluginPreloader when launching FO:LON
- go back into MO2 Fallout London instance
(I'll use for the next steps as reference the (picture: Start Options.jpg) !!!)
- click on the pulldown menu (where F4SE should be visible) and select edit (Picture point 1)
- in the new opened picture ensure that F4SE is selected (Picture point 2)
- add into the line Startparameter the following (exactly as written) -forcesteamloader (Picture point 3)
- apply changes, click OK
- close MO2 (just to be on the safe side)
- if you want you can delete your safe folder now (if you previously packed and stored it somewhere)
- re-open MO2
- change to Fallout London instance (if not in already)
- Select F4SE (left beside the Start button)

AND LAUNCH FALLOUT LONDON

That was all !

Pro Tip: you can use a Mod Organiser 2 shortcut to directly launch Mod Organizer 2 with the instance of Fallout London started, if you right-click the shortcut, select properties change to Shortcut TAB, append to the Target "Mod Organizer 2.exe" the parameter -i "Fallout London" (Or whatever you've called the Mod managers Gamefile folder.). Apply and OK. Now when double clicking the shortcut, Mod Organizer will start with the correct instance active (in this example Fallout London).(This works for all MO2 instances).
(This tip is quite helpful, because if you change the MOD Organizers 2 Icon also to an icon that resembles Fallout London, you now have a nice start picture to start playing Fallout London with)


This guide was written by adtbm in January 2025 - Thanks to Team FOLON for this incredible MOD and thanks to GOG for the cooperation with Team FOLON

Good to see gog getting Fallout 4 in Stable version
i had no idea you need to do so much gymnastics just to install 1 mod

You don't. That makes it MUCH more complicated than it needs to be.

I just:

Downloaded and installed GOG FO4.
Use the FO4 launcher to setup your resolution and other settings to make sure FO4 base game is working for you.

Downloaded and installed GOG Fallout London Mod.
Launch the first time with Fallout London Launcher (shortcut on desktop), make sure click install in that.

Click play, and enjoy Fallout London.

(You may need to use the FO4 launcher again to readjust some settings).

Future launches can be done from the Fallout London desktop, Icon, or a link F4SE shortcut.

I have no idea why people have so much trouble with this. I expect that it's thinking that "intsall Fallout London" means it's done. That really places the files in a holding area. You just need to use the Fallout London shortcut and click install in there as well, which will actually move the files to the base install, and you need to do this if/when you patch it.

It's great to see, that i did all this work for some people who aren't even able to read the Topic of this post

This Guide is for people that want to use Mod Organizer 2 to install Fallout London, so they can keep their modded version of Fallout 4 intact WITHOUT installing a second time Fallout 4 (just to be able to play Fallout London as well)

So thanks to both of you for commenting without even reading the headline of my post !!!

You didn't actually say that was the goal in your first post. So it looks like this is just intended as how you normally install Fallout London.

It's not so much that we didn't read, but we didn't read your mind for obvious reasons. Maybe it's implied if you read the entire wall of text, but it should be clearly stated right the beginning, because who is going to read the whole thing if it doesn't seem to be what they need?

Also this is still MUCH more work than just installing FO4 a second time.

My solution for keeping my original modded install was to just rename my original directories, and install a second time as indicated in my post. Very simple.

I can switch between my modded original game, and FOLON install by changing directory names. Which I have done several times.

Did you read the title of the Topic subject ???

It clearly states :
How To: Fallout London 1.02 (GOG) with Fallout 4 GOTY 1.10.163 (GOG) and Mod Organizer 2 - Guide
Can it be more precise ???

i even repeat myself in the first line of my post:
Quote: "This is my Guide, with my collected experience (during the process) on how to install Fallout London with Mod Organizer 2"
As we say in german: "Wer lesen kann ist klar im Vorteil" or in english "He, who's able to read has an advantage"

Which is NOT the same as what you said in a later post: Simply saying here is how you install Fallout London, with MO2, Is far from: Letting people know this is so you can keep your current modded version intact, without doing a second install.

You didn't mention that vital bit of information, until you started complaining that people were missing the point...

A point you didn't reveal until you started complaining.

Now you try spinning in circles ?
first you're brabbeling to tell everybody over here, that i did not state in my original post or in the subject topic, what my guide was about which i proved you wrong !
Now you're refering to later posts, which does not contradict my original post, if you would have a clue how MO2 works, but since you can't read and only want to debate, i'LL leave you to your brillant (and in fact not user friendly) idea, to always rename your directories. Yes, always changing game directory, my games folder and appdata is surely a far more convenient and simpler way than just changing the instance after succesfully installing FO4 and FOLON in MO2. *ROFLMFAO*

So i have proven to you, that you can't read, so my last quuestion for you: what is your intention here ? finding somebody to discuss with ?
To be able to discuss you should have valid arguments (what you don't have - proven above). And you can only argument, if you know what you're talking about and since you've never fully read my first point, you have no valid argument.

Now i'll ignore you, you're not worth my time and you've proven it, to everybody who is able to read !
...or like my late Dad used to say: "Don't try to argue with a Moron. He'll pull you down to his level and then wins by expertise"

You made a mistake, instead of just getting it, you got hyper defensive and attacked people for not getting something you didn't initially disclose.

Classy.


For others don't waste your time with this overly complex "guide".


You can just do two step install like I indicated earlier.

If you want to keep your previous install. Just change directory names. Simple quick and easy.

Big complex guides like this are prone to errors and probably the other half the reason people have difficulty getting FOLON working.

KISS principle is usually the way to go.

"his Guide is for people that want to use Mod Organizer 2 to install Fallout London, so they can keep their modded version of Fallout 4 intact WITHOUT installing a second time Fallout 4 (just to be able to play Fallout London as well)"

I also dont see where that info is sorry.
I never installed/played Fallout4. Can the Lonodn one click install be futher enhanced with MO2 with other mods? Would that also require a special install like this guide or is that not needed ?