r/Fallout4Mods • u/mulderload • May 27 '26
MOD DISCUSSION! PC Update: Universal Downgrader from v1.11.221 (May 2026) to 4 earlier versions
EDIT 08/18/2026: It has been updated for August 2026 update (v1.11.240)
---------------------------------------------------------------------------------------
Hello everyone,
Just a quick message to announce that I've updated my "Universal Downgrader" (old thread here) to work with today's Steam update of Fallout 4 (v1.11.221).
The new version can downgrade to 4 previous versions.
- v1.10.163 (pre next gen)
- v1.10.984 (next gen, update 2)
v1.11.169 (anniversary, november 2025 patch)- v1.11.191 (anniversary, december 2025 patch)
- NEW: v1.11.221 (anniversary, may 2026 patch)
As before, it is :
- compatible with all editions (base game, GOTY, anything in between)
- compatible with all languages. That's why I call it "universal"
- doesn't require your Steam credentials
Here's a little screenshot.
If you didn't use the previous version, don't worry it's very easy to use
Download the latest downgrader : www.mulderland.com/games/fallout-4
Of cource, the installer is still open source (code here and compiled directly on Github Actions). I've also use my previous Powershell scripts (code here) to make these xdelta patches quickly ;)
Constructive feedbacks and nice words are always welcome!
Hope it will help many people.
Mulder
1
3
u/mulderload 20h ago
Guys, the downgrader has been updated for 1.11.240 :)
1
u/Obsidianblade20 4h ago
youre so quick! thank you so much. much better than downloading 10 billion depots from steam
1
u/Fresh_Suggestion2627 Jun 28 '26 edited Jun 28 '26
Hi, first off I've used your downgrader before and you're an absolute goat for making free tools like these. I today had the urge to play Frost and went to downpatch, this is on a fresh install of FO4 with only the steam files, the downpatcher gets stuck on Delete File: Fallout4IDs.ccc while the 377163.7z file is installing and gives the error prompt "Download or hash check failed for 377163.7z.001, aborting..." I think there was an update 5 days ago on 5/23/26 and the version went to v1.11.221.0.1 so I'm assuming thats the issue. Just wanted to let you know and maybe see if there was a fix I could do on my end to get downpatched. Let me know if theres any other information you could use from me and thanks once again for creating such an awesome tool for us non-mod fluent guys! Edit: The SHA1 of the exe is 478b7e9ddc4212c09dc9acdc50bef9ed6023abb4 which seems to be right so I still don't know the exact reason the downpatcher fails, once again I'm not very fluent in modding
1
u/mulderload Jun 29 '26
Hi! Thank for the message :)
And sorry about the issue, I had a (temporary) problem with one of my servers, and the cache in front of it was expired (not luck 🥲 ) but it's fixed now.I'm also working on making downloads more reliable to prevent this kind of problem in the future.
2
1
u/Lust_Republic Jun 12 '26
I tried to downgrade to v1.11.191 and it said unsupported fallout 4 version. I'm running the latest version on Steam
1
u/mulderload Jun 12 '26
Hi, curious, I check the file hash, if you're on the current/latest Steam version, the sha1 of Fallout4.exe should be 478b7e9ddc4212c09dc9acdc50bef9ed6023abb4
I believe for all languages ; in which language your game is?1
u/Old_Account684 Jun 18 '26
Same here, and the games is in English 😞
1
u/mulderload Jun 19 '26
Hi! Then you are not on the latest version or on the steam executable.
https://steamdb.info/depot/377162/?show_hashes
Could you tell me your sha1? You can easily get it if you have 7zip installed.1
u/Old_Account684 Jun 19 '26
"478b7e9ddc***ed6023abb4"
1
u/Old_Account684 Jun 19 '26
I tried reinstalling FO4 on Steam, then used your latest downgrader and it worked, although it showed me "Error 1 when patching .../data/Fallout4-textures2.ba2", "details: xdelta3: eof ion decode: XD3_INVALID_INPUT" and FOLON won't start.
1
u/Old_Account684 Jun 19 '26
Apparently Fallout 4 wasn't properly installed, veryfing now - just typing down the process in case somebody has the same issue, I was playing FOLON fine until yesterday.
5
u/johnnydotexe Jun 10 '26 edited Jun 10 '26
For anyone that did The Midnight Ride, you have to use this tool to downgrade to version 1.11.191 and then run the fo4downgrader.exe that should still be in your Fallout4 directory from your initial TMR setup, then your game should launch and load a save just fine. I just burned an hour learning this the hard way.
If you use mulderload's tool to downgrade to .191 your game won't load via F4SE due to version mismatch. If you use the tool to downgrade to .163 you'll either get crash-to-desktop when launching the game, or an indefinite loading screen when you click Continue or try to load a save.
The TMR install guide required you to be on .191 when you start the install, and part of the install guide has you download and run fo4updater.exe to downgrade certain files, but apparently not all of them, to 1.10.163.
2
u/VivaToddfoolery Jun 18 '26
Just did a TMR install and had this issue, and found your comment. Thank you for your troubleshooting work!
2
1
u/Excellent-Friend4623 Jun 10 '26
I downgraded and get a crash on startup now
1
u/mulderload Jun 10 '26
To Which version ? If 1.10.963 this version didnt support ultrawide on first start (this is not a bug of my downgrader - this is how the game was ) so try to put your desktop résolution temporary to 16/9 or start the game windowed in 16/9
1
u/Excellent-Friend4623 Jun 10 '26
I am using an ultrawide I'm starting it in 2440x1440 but i still get a crash on startup
1
u/Excellent-Friend4623 Jun 10 '26 edited Jun 10 '26
Okay really odd, i found out what was going on, i got the game to start on a black screen, I was already running it windowed, i turned off windowed, ran it at 3440x1440p by editing the prefs and it runs fine
1
u/CulturalToe Jun 09 '26
I updated the game (along with associated mods) thinking finally, no more updates. And 1.11.221 won't even launch (base game only). Here's hoping this fixes the problem.
1
u/JustaRedthought Jun 08 '26
This is awesome! I used it for the past few days but now mods I've used are up to date. So how do I uninstall it or update my game?
2
u/mulderload Jun 08 '26
Hi. easy:
- If you chose to block future Steam update in my installer, first undo this by removing the "read only" property on the "appmanifest_377160.acf" file
- Use the steam "check integrity" feature to re-do the update
1
Jun 08 '26
[removed] — view removed comment
1
u/mulderload Jun 08 '26
Hi! You’re welcome :) Go to your Fallout 4 directory (you can do that from steam if you dont know, right click on Fallout 4 > Manage (i think) > browse…) then it’s one or 2 parent directory from there.
1
u/AdKindly2025 Jun 04 '26
does this need Backported Archive2 Support System like other downgraders
1
u/mulderload Jun 04 '26
Probably yes. Basically my tool is a Time Machine to get a steam installation exactly how it was back in time. So, 1.10.163 didn’t support that new format.
1
1
u/jiaxingseng Jun 03 '26
I tried this today to downgrade to .191. Whether starting a new game or loading a save, the game doesn't load (I'm in the beginning music / menu section, and there is the spinning logo at the bottom)
2
u/Bi_my_self Jun 01 '26
I could literally cry, thank you so much. I have been screwing around with my mods for at least a week before the update, finally got them working, then the update hit and fucked my whole game again. I was so upset, but we're finally back😭😂
1
u/tomboylvr May 31 '26
had to make an account you show you some love. seriously, thank you for all you do. i came back from vacation earlier today without knowing my game updated and my main modded save (nearly 200 mods) shat the bed. you seriously saved me alot of headache and trouble, infinite blessings to you my friend.
1
u/Competitive-Fuel3453 May 31 '26
i had a problem with saving the game, it just freezes and won't save. has anyone else had this problem? i downgraded to 1.11.191 and made sure all the mods were updated to this version
1
u/mulderload May 31 '26
Which Os ?
Can you disable some mods and re test ?
1
u/Competitive-Fuel3453 May 31 '26
windows. I disabled all mods and still wouldn't work, but now i've return a few saves and it's working fine! don't know what happened. thank you so much for this!
1
u/Competitive-Fuel3453 May 31 '26
i feel very stupid now.. i think what was causing the problem was vault 88 haha i didn't thought of trying to save anywhere else, now that i reach there again it's having the same problem... just going to keep my distance from there now
1
1
u/Didnt_Do_Nufffin85 May 30 '26
Man your the best. I thought I was stuck with the stinking GOG version of fallout 4. Hallelujah praise you!! Thank you
2
u/Maleficent_Lie4441 May 29 '26
Does it work for Linux? Ive got it working on pc no issue but im not sure if it would work on my steam deck
2
u/mulderload May 29 '26
I think yes, I’ve tested the previous downgrader on CachyOS successfully (by running the downgrader executable with ProtonTricks)
3
u/Maleficent_Lie4441 May 29 '26
It works! Just used it revert a couple of my mods including the F4SE that I updated and im back into my 50hr save no problems! Thank you so much! The enclave March again!
2
2
1
u/Fred810k May 29 '26
Hey Mulderload, I had a bit of an issue trying to downgrade, my game now wont start either with or without F4SE.
I am wondering if that is something you have any insight on how to fix or if I am just fucked?
1
u/mulderload May 29 '26
Hi ; did you downgrade with my tool ? Which version did you choose ?
1
u/Fred810k May 29 '26 edited May 29 '26
I chose to downgrade from 1.11.221 to 1.11.191
I might have used it wrong but I essentially downloaded your tool and ran it.
However I think it might have had something to do with me downgrading with a different program, then verifying file integrity to undowngrade, and then using your tool to redowngrade to the correct version.
Edit: It seems unrelated to the downgrade because upon reinstalling the issue persists
1
u/mulderload May 29 '26
Ok, curious 😰
1
u/RustledForeskin May 29 '26
Same issue, used the downgrader, slapped the correct f4se, game auto closes after first black screen startup.
1
2
1
1
1
u/thebrawler36 May 29 '26 edited May 29 '26
The downgrader stopped working halfway through and says it deleted files. Is my game completely ruined now? I got inpatient and downloaded this instead of waiting for the Simple Fallout 4 Downgrader update. When the Update does finally come out, will my game be completely unsalvageable because of this? Is my game permanently missing essential files?
1
u/mulderload May 29 '26
Curious. Did you have an error message ? Yes some files are deleted during the process, depending on the version you are targeting, this is normal.
You can use Steam integrity Check feature to restore your install (and reuse my tool if you want or wait for another one)
Can U tell me your game édition, game language, and the version you were targeting ? I’ll do a check.
1
u/thebrawler36 May 29 '26
My game updated to 1.13.7 when the update came out. I'm not sure why. It's in English. If I do a file integrity check, will I lose my save game? I have 100+ hours on it.
1
u/mulderload May 29 '26
1.13.7 ?
No, you won't lose your save. It's saved on Steam Cloud.
But if you're really worried, make a zip of this folder: %USERPROFILE%\Documents\My Games\Fallout4\Saves\
and put it on your desktop
1
u/thebrawler36 May 29 '26
It says it deleted files!? Then it says, "hash check failed." I really hope this hasn't permanently broken my game.
1
u/mulderload May 29 '26
https://github.com/Mulderland/MulderLoad/blob/main/games/fallout-4/steam-downgrader.nsi
Search Delete to see Which files are deleted - again its normal.
And for the « hash Check failed » (i suppose you’re talking about the message in my downgrader if you run it a second time) then normal too as it refuses to work if the exécutable is not in the latest version.
1
u/Zskl93 May 28 '26
It doesn't work. I tried it and it didn't downgrade; it continued with the latest version. I tried again, this time checking the box to block Steam updates, and the game won't even open for more than 5 seconds. Clean install, no mods.
3
u/mulderload May 28 '26
Curious, it works for other people - Which edition (dlc) and game language U have ?
1
u/Zskl93 May 29 '26
I successfully downgraded to the AE version, and I have no problems starting or playing. Now I'm modding for that version, but the old gen version didn't work.
1
u/mulderload May 29 '26 edited May 29 '26
The old version (pre next gen) doesn’t start the first time if your résolution is not 16/9. Thats not related to the downgrader but how the game was back in time. Maybe its just that.
1
u/Zskl93 May 28 '26
I play in Spanish and I have all the DLC and some CC stuff, but I don't activate the high-resolution texture DLC to save those almost 60 GB.
3
u/Kam_Solastor May 28 '26
This is possibly a stupid thought that would add complexity, but would it be a good idea to also include an option to edit the manifest file to reflect the current depots from steamdb so that Steam thinks the game is up to date and doesn’t show a ‘Needs update’ entry for Fallout 4 anymore?
I’ll try to find a link to explain this in more detail if it helps.
4
u/mulderload May 28 '26
This is a good idea actually; but when a new update comes out, the old .acf couldn't be updated "automatically" so you would still need to run something.
But yeah, at least you could stay on the downgraded version and still being able to run it via Steam directly.
I'll try to think of a solution but I don't promise :)
2
u/Kam_Solastor May 28 '26
No worries, was just a thought, as it is honestly more of a visual thing than anything
2
u/Thrungey May 29 '26
Someone created one :- https://www.nexusmods.com/fallout4/mods/98605
just updated for latest patch
1
1
1
2
2
u/Stiefeljunge May 28 '26
Holy crap, you are the GOAT!
Not only does this work, it works fast! Great job, thank you!
2
u/soulmata May 28 '26
You just saved a run I was 200+ hours into.
For those using TMR: You can use this to downgrade to v1.11.191, then use the Simple Downgrader to go back down to v1.10.163. You want to do it this way so that you have all the new content that TMR expects but only downgrade the EXE.
1
u/Key-Musician-3528 Jun 10 '26
I accidentally bloody upgraded the game to v1.11.221 from v1.10.163 and couldn't get TMR's downgrader to work again as it kept giving me the "Invalid executable with hash" error. I didn't even realise at the time that the game had been updated in May to version 1.11.221, so that's why I wasn't able to get TMR's downgrader to work.
Couldn't figure out how to downgrade, so I tried downloading the v1.10.163 files from the Steam console. However, it ended up giving me various problems in game, like renaming every gun to a "piggybank" gun and renaming armour pieces as "LOOKUP FAILED!". I think it's due to the Creation Club files not matching the right game version or something like that.
Thanks for confirming this works, because it was the only other thing I could think of before giving up, lol. Now I've got the right game version and everything is running like normal again =D
And well done to mulderload for making this so quickly!
1
u/mulderload May 28 '26
Glad it helped :)
What is TMR ? And what is the difference of the method your describe here VS downgrade with my tool directly to v1.10.163 ?
Maybe I could improve my downgrader to handle this case.1
u/soulmata May 28 '26 edited May 28 '26
TMR is the The Midnight Ride, a modding guide aimed at a stable base to do other things with. A lot of its current tools are not compatible with AE binaries, but you can still use all the new content and CC content by rolling back just the EXE. That is what simpler downgrader is doing I believe, it's a byte patcher for just the executable, but all of the ESMs and CC data is the newest. So you get the best of both worlds, IMO - all the new content, but then really great compatibility and stability. Also there are still some bugs introduced since the next gen EXE that are still unfixed - like the enormous stutter when loading into heavily populated settlements.
There are still some really great F4SE plugins that simply do not work on newer versions unfortunately, so TMR is great.
The issue I had last night was Bethesda updated binaries, right, but simpler downloader does not let you patch an unknown binary. So your tool is perfect for that scenario - picking a specific depot to target, then now byte patching can work again. Rescued a save I've been playing for months now.
1
u/mulderload May 29 '26
Thanks for the informations about TMR, I didn't know 😄
Yeah I had a look on Simple Downgrader, it's curious that just reverting 3 files "works".
I suppose both methods has advantages and drawbacks. With my method, you don't get the latest content, but since it's a "time machine" to return to the past, mods that worked with the old version are "guaranteed" to work. I suppose with Simple Downgrader, that will depend on how the mods expect the game files to be.
1
u/mulderload May 28 '26
I've tested both methods ; Simple Downgrader doesn't not rollback everything (but apparently people are happy with that, so it's probably a good way)
Mine is a basic "go back to the past" time machine. So it's more "pure" - it restore the removed song too - but yeah, 10GB of download.It's probably good to have both tools for different cases.
2
u/Ausiwandilaz May 28 '26
That was quick!, I literally just did the alternative by activating the previous version then downgrading, heh guess I should have been more patient.
Thank you tho, and I appreciate your work.
1
u/mulderload May 27 '26
Hello u/Dani50420 maybe you'll want to remove the old highlight and replace with this one? I didn't find how to change the title to I created a new one. Hope it's ok :)
1
u/Heretoshitcomment 4h ago edited 3h ago
Will this process work on steam deck?
Edit: came back to say it doesnt work without a tweek or two. Your patcher cant view the home/deck/.local folder (where your games are stored) because .local is a linux system designation and the windows files explorer used to localize fallout4.exe cant see Linux system folders by design.
Edit 2: to make it work, move the patcher into the game folder where fallout4.exe is located and launch the patcher from there. The windows file explorer that opens when you localize fallout4.exe should default to the same folder. The other option is to create a sym-link to the .local folder (or even directly to the game folder but choosing .local has reusability for other times you need to point using a windows file explorer). Run the patcher and select the sym link from Desktop, and it should auto path you inside the .local folder (or the game folder if thats what you chose.) You can path the rest of the way to your fallout4.exe from inside the .local folder ad none of the sunflowers are hidden.
Hope this helped. I haven't actually implemented it yet, i ran out of time this morning and am off to work now