Satisfactory mods not working after update 1.2.5? SML and mod manager status

As of November 2026, the current Satisfactory version is patch 1.2.5.0, released on November 4, 2026. Satisfactory Mod Loader (SML) 3.12.0 supports this version. If your mods stopped working, the most common causes are an out-of-date mod, a mod built for the old engine, or a game launched with mods switched off. Open Satisfactory Mod Manager (SMM), update everything, check that nothing is marked outdated, and launch the game from SMM.

In this guide

1. Quick fix and current framework status
2. Find your symptom
3. Mods stopped working after a Satisfactory update
4. Mods are enabled but don’t show up in game
5. ‘Plugin SML failed to load’ or crash on startup
6. Game won’t launch through Satisfactory Mod Manager
7. How to read FactoryGame.log
8. Multiplayer, crossplay and dedicated servers
9. Protect your save
10. How to get back to vanilla Satisfactory
11. FAQ

Quick fix: why your Satisfactory mods aren’t working (November 2026)

In most cases the game changed and your mods didn’t. Satisfactory has run on Unreal Engine 5.6.1 since Update 1.2 reached Stable on June 2, 2026. Mods built against the older 1.1 engine either fail to load or crash the game on boot.

The five-step quick fix:

1. Open Satisfactory Mod Manager. It updates itself, so let it finish.
2. Click update all, and confirm that SML shows version 3.12.0.
3. Look for any mod marked outdated or incompatible, and disable it.
4. Launch the game with SMM’s Launch button, not from a desktop shortcut you made before the update.
5. If you need to play right now, flip SMM’s global Mods switch off and play vanilla until your mods are updated.

Current framework and core tool status

Every Satisfactory mod depends on the loader and the tools below. Versions come from the SML page on ficsit.app and the satisfactorymodding GitHub releases pages for SML and SMM, checked in November 2026.

SMM was rewritten as v3 for Satisfactory 1.0. The rewrite added dedicated server management for both local and remote servers. An SMM v3 install updates itself, so you don’t need to download it again after a game patch (docs.ficsit.app, “Installing Mods and Using the Satisfactory Mod Manager”). The thing to watch is SML.

Find your symptom

Start with what you can see on screen. The table points you to the cause that fits most often, the fix, and the section of this guide that covers it.

Mods stopped working after a Satisfactory update

Mods usually break after a patch because they are compiled code tied to one engine version and one set of game headers. When Coffee Stain Studios changes either one, each mod author has to rebuild and re-release the mod. Until that happens, the mod is broken for you.

Major updates, and any update that changes the Unreal Engine version, have historically made mods incompatible (Official Satisfactory Wiki, Modding page). Incompatible mods can make the game unplayable and have to be removed through the mod manager. An updated version is never guaranteed.

Satisfactory updates that broke mods

What changed in 1.2 (Unreal Engine 5.6.1)

Update 1.2 replaced the engine underneath the game, which is the most disruptive kind of patch for mods. Most mods need recompiling against the new engine and headers, as the developer migration guide “Updating from SML 3.11.0” on docs.ficsit.app spells out. So even a simple mod that changes a stack size had to be rebuilt.

A mismatched mod can do worse than fail quietly. According to DoomHosting’s 1.2 launch guide, an unofficial server-host write-up, a mod built against the 1.1 (UE 5.3) binary interface can crash the game on boot. That fits the wiki’s official warning that incompatible mods can make the game unplayable, and it explains reports in late spring along the lines of “the latest update broke all the SMM mods”. One leftover mod was enough to stop the whole game from starting.

Here is how the timing worked out. Update 1.2 hit Stable on June 2, and SML 3.12.0 followed on June 6. Any mod that needs SML could only be updated after that date. Larger content mods with many dependencies, such as Satisfactory Plus or Refined Power, have more to rebuild than a single-feature mod. Check each mod’s own ficsit.app page for its current status instead of assuming it is ready.

Audio mods and patch 1.2.4.1

If your audio mods went silent during the 1.2 cycle, the cause was in the game, not in the mods. Patch 1.2.4.1 (October 12, 2026) turned Audio Routing back on, so Metasound works by default again. That fixed the audio mods that broke after the previous patch. The same patch also moved the game’s internal Wwise version to 2025.1.6 and reset Engine.ini to its original state.

If audio mods are still silent on 1.2.5.0, the mod itself is probably out of date. Check its ficsit.app page. Also check for an old custom Engine.ini tweak that a mod guide told you to add.

Stable vs Experimental: the branch must match

SMM will only install a mod version that matches your current branch, Stable or Experimental (Official Satisfactory Wiki, Game mods page). Mod versions built for Experimental won’t install on Stable, and the reverse is also true. From March 17 to June 2, 2026, many players were on Experimental 1.2 while most mods still targeted Stable 1.1.

To check your branch on Steam, right-click Satisfactory, open Properties, then Betas. “None” means Stable. SMM reads the install you select at the top of its window, so make sure it points at the branch you actually play.

When a mod is abandoned

Some mods never come back after an engine change. If a mod’s ficsit.app page shows no 1.2-compatible release months after SML 3.12.0, plan as if it won’t return. You have three honest options:

• Stay on the old version. This is only possible if a store branch for it exists, which is rare.
• Remove the mod and accept the loss. Keep a backup of the save from before you removed it.
• Look for a replacement. Check ficsit.app for a mod that does the same job and supports 1.2.

If the Update button in SMM does nothing, there is nothing newer to download. SMM only offers a version that the author has published for your game version. There is no set waiting time. SML itself took four days after 1.2 Stable. Individual mods have taken anywhere from days to months.

Mods are enabled but don’t show up in game

If SMM lists your mods as enabled but nothing appears in game, the mods usually aren’t being loaded at all, or they loaded but are waiting behind something you haven’t unlocked yet. Work through these checks in order.

Check the switches and the profile

SMM has two separate controls:

• The global Mods switch. When it is off, SMM removes mod loading for that install and nothing loads, whatever is ticked.
• The per-mod toggle. Each mod can be turned off on its own while the rest stay on.

SMM also works in profiles. If you made a new profile or imported one from a friend, the mods you see ticked might belong to a different profile from the one that is active. Select the right profile, then launch.

A profile that has been around since before 1.2 can also cause trouble. If it carries old version locks, it can keep requesting mod versions that don’t exist for 1.2. A useful test is to create a fresh profile, add one simple mod and launch. If that mod shows up, rebuild your list in the new profile.

Launch from SMM, and know what launching outside it does

Starting the game from Steam or Epic still loads any mods that are installed (ficsit.app documentation FAQ). So launching outside SMM is rarely why mods are missing. More often the files on disk are out of sync with what SMM shows. Press Launch in SMM once so it can apply the profile, then use any launcher you like.

Missing dependencies and locked content

Many mods depend on library mods such as ContentLib. SMM installs dependencies automatically. If a dependency has no 1.2 release yet, though, the mod that needs it can’t load either.

Some mods also load fine but add content you haven’t unlocked yet. New buildings and recipes often sit behind a HUB milestone, a MAM research or a new schematic. Before deciding a content mod is broken, check its ficsit.app description for how to unlock it.

‘Plugin SML failed to load’ or crash on startup

“Plugin ‘SML’ failed to load because module ‘SML’ could not be found” means the game found SML’s plugin entry but couldn’t load its compiled module. There are three usual causes: the SML files are built for a different game version, they are partly missing, or they are corrupted. A crash on the loading screen with SML present usually comes from one incompatible mod.

Why batches beat guessing

Halving your list finds the bad mod in a few launches. Say you have 40 mods: disable all of them, then turn 20 back on. If the game boots, the problem is in the other 20. Split that half into two groups of 10, and keep going. Five or six launches are usually enough to find a single bad mod.

Do you have to delete everything and reinstall?

Usually not. Deleting the Mods folder inside the game install is enough to clear broken binaries, because SMM downloads them again. Reinstalling the whole game is a last resort. Your saves live in a separate folder, so neither step touches them. Verifying files through Steam or Epic restores any vanilla files that a manual mod install overwrote.

Game won’t launch through Satisfactory Mod Manager

When SMM won’t launch the game, the usual reason is that it can’t find the install, or that the install it found isn’t the copy you play. Fix the detection first. Launch problems usually go away once detection works.

‘No Satisfactory installs found’

SMM finds the game by asking the Steam and Epic Games Store apps where it is installed (ficsit.app FAQ). If you copied the game folder to another drive by hand, the store apps don’t know about it, so neither does SMM. Pirated copies are not supported.

Steam vs Epic installs

For future moves on Steam, use the client’s own tools: Valve’s Steam Support article on library folders describes creating a library on the target drive first, then moving games from the Storage tab. A per-game route also exists through right-click, Manage, then Move install folder. Either way Steam keeps track of the new path, so SMM still finds it.

If SMM opens without a visible window, or mod downloads keep failing, close it fully from the system tray and start it again. If downloads still fail, check whether security software is blocking it. SMM v3.0.2 fixed a known Epic detection bug, which is another reason to let SMM finish updating itself before you troubleshoot.

Linux and Steam Deck

SMM runs on Linux, including the Steam Deck in Desktop Mode, and SML 3.12.0 lists Linux support. The standalone Linux build of SMM needs WebKitGTK (webkit2gtk). The SMM v3.0.0 release notes on GitHub name libwebkit2gtk-4.1, while older guides mention webkit2gtk-4.0, so install the package your SMM release asks for. A blank or crashing SMM window on Linux almost always means this library is missing.

How to read FactoryGame.log

FactoryGame.log is the game’s own record of each launch. It names the mod that failed far more reliably than a crash popup does. You’ll find it at %localappdata%\FactoryGame\Saved\Logs\FactoryGame.log.

Get a useful log

1. Reproduce the problem once, so the newest log covers it.
2. Copy FactoryGame.log right away. The game overwrites it on the next launch and keeps older logs with timestamped names.
3. To watch the log live, add -logs to the game’s launch options. A debug console then opens next to the game. ContentLib’s troubleshooting docs recommend the same flag.

What to search for

• “Error”, then the mod’s reference name. Reference names are the short IDs shown on ficsit.app, for example SML for the loader.
• “Fatal” near the end of the file, for crashes.
• “Warning” lines that mention a mod’s reference name. These often point to a missing dependency or an asset that failed to load.
• The SML version line near the top, to confirm you are really running 3.12.0.

Multiplayer, crossplay and dedicated servers

Modded multiplayer works only when everyone runs the same required mods at the same versions. Crossplay works only when nobody runs mods. Most “friends can’t join” reports come down to one of those two rules.

Friends can’t join my modded game

A client can only join if it has the same mods as the host or server (docs.ficsit.app, “Installing Mods on Dedicated Servers”). If versions don’t match, the game blocks the join. The easiest fix is a shared profile: export it from SMM on the host, send the file, and have each friend import it. That way everyone has the same mod list and the same versions.

Version locks help keep a group in sync after updates. In SMM you can lock a mod to an exact version, or to that version or newer, so one player’s auto-update doesn’t split the group.

Does this mod work in multiplayer?

Not every mod behaves the same way online. Mods fall into three groups, and each needs installing in a different place. The mod’s ficsit.app page is the place to check before you add it to a shared game.

Two edge cases cause most confusion. First, a mod that wasn’t written with multiplayer replication in mind can work perfectly for the host while clients see missing items, broken buttons or desyncs. Check the mod’s description and known issues before you blame your setup. Second, ficsit.app lists the targets each mod version supports, including the server targets for dedicated servers. A mod with no server target can’t run on a dedicated server, whatever you copy over.

Crossplay and mods

Patch 1.2.5.0 (November 4, 2026) added crossplay between Steam, Epic, PlayStation 5 and Xbox Series X|S. Every player needs a free Epic Games account. Crossplay sessions must be unmodded (1.2.5.0 patch notes), which follows from the fact that console players can’t run mods. Crossplay covers active play only. There is no cross-progression, and the save stays on the host’s platform (Official Satisfactory Wiki, Patch 1.2.5.0).

So, can you still join your console friends if you have mods? Yes, once you flip the Mods switch off in SMM. Your modded saves aren’t touched. Turn the switch back on when you return to your own game.

Mods on a dedicated server

A Satisfactory Dedicated Server needs its own copy of SML and the server builds of your mods. SMM v3 manages local and remote servers directly, including over SFTP, and the official docs recommend handling client and server through one profile. Don’t copy your local Mods folder to the server: client builds don’t run on a dedicated server and fail with vague errors.

Work through those four rows in order when a server stops accepting players after a patch.

Protect your save

Satisfactory saves survive most mod changes, but content that comes from a missing mod does not. Back up before any game update and before you remove a mod, and you can always undo the change.

Adding and removing mods mid-save

Adding a mod to an existing save is usually safe. Removing one is riskier. When you load a save without a mod it relied on, that mod’s buildings and items can’t be loaded. Once you save again, they are gone for good. Removing a building mod from an established factory can therefore leave holes in your production lines.

Recover your mod list from the save header

If you lost your profile, the save file can still tell you what it used. SML writes the mods and versions used by a save into the save header (ficsit.app FAQ). Line 3 holds a JSON object with a Reference, Name and Version for each mod. Open a copy of the .sav file in a text editor and read that line. Then rebuild the profile in SMM, mod by mod.

How to get back to vanilla Satisfactory

To play unmodded, turn the global Mods switch off in SMM. That is the quickest option and the easiest to undo. If SMM itself won’t run, deleting the Mods folder in the game install does the same job.

The last row catches a lot of players. Uninstalling Satisfactory Mod Manager leaves your mods in place (ficsit.app FAQ). The files stay in the game folder and still load when you start Satisfactory from Steam or Epic.

Stop the game updating itself

You can’t fully block updates on every store, but you can control when they happen:

• Steam: Properties, Updates, then “Only update this game when I launch it”. Steam still needs the update before the game will start, so this only delays it.
• Epic Games Store: In the library, open the game’s Manage settings and turn off Auto-Update. You can then decide when to accept the patch.

Delaying an update gives mod authors time to catch up. The tradeoffs are that you can’t join friends on the new version, and crossplay needs the current build. For most players the better habit is to back up before each update and check SML’s ficsit.app page before playing.

FAQ

Why aren’t my Satisfactory mods working anymore?

Usually because the game updated and your mods haven’t. Update 1.2 moved Satisfactory to Unreal Engine 5.6.1, and most mods needed rebuilding for SML 3.12.0. Update everything in SMM and disable anything marked outdated.

Why are my mods failing to load?

The usual causes are a missing dependency, an outdated mod, a branch mismatch between Stable and Experimental, or the global Mods switch being off. FactoryGame.log names the mod that failed.

Why isn’t my game launching through Satisfactory Mod Manager?

SMM probably can’t find the install. It only finds installs that Steam or Epic know about. Add a moved folder as a Steam library folder, or reinstall through Epic, then restart SMM.

Will Steam ban me for using mods in Satisfactory?

No. Mods from ficsit.app change only your local game files, and Steam doesn’t ban accounts for modding Satisfactory. The real risks are crashes and lost modded content in saves, so keep backups. Turn mods off before you report a bug to Coffee Stain.

How do I fix ‘Plugin SML failed to load’?

Update SML to 3.12.0 in SMM. If the error stays, close SMM, delete the FactoryGame\Mods folder, verify game files, and let SMM reinstall SML and your mods.

How long does it take for mods to update after a Satisfactory patch?

There is no fixed time. SML 3.12.0 arrived four days after 1.2 went Stable. Individual mods depend on their authors, from days to months, and some never update.

Can I play crossplay with mods?

No. Crossplay sessions in 1.2.5.0 must be unmodded, and dedicated servers are excluded. Turn the Mods switch off in SMM to join console friends.

Do my friends need the same mods as me?

For both-sided mods, yes, at the same versions. Client-side mods only need to be on the player who uses them, and server-side mods only on the host or server. Sharing one exported SMM profile is the simplest way to match.

Why does a mod work for the host but not for my friends?

Either the mod is meant to run on one side only, or it wasn’t built with multiplayer in mind. Check the mod’s ficsit.app page for multiplayer and dedicated-server notes before reporting it as broken.

Do Satisfactory mods work on PS5 or Xbox?

No. Console players can’t run mods. SML and SMM support the PC versions on Steam and Epic only, on Windows and Linux.

Will removing a mod break my save?

The save will still load, but buildings and items from that mod are deleted once you save again. Back up first. You can rebuild the mod list from line 3 of the save header if you need to restore it.

How do I play vanilla Satisfactory again after using mods?

Flip the global Mods switch off in SMM, or delete the FactoryGame\Mods folder. Uninstalling SMM alone leaves your mods in place, and they still load.

Do I need the Experimental branch for mods?

Only if your mods target Experimental. Most mods target Stable, and SMM won’t install a version built for the other branch. Stay on Stable unless a mod’s page says otherwise.

Before the next big patch, make one habit routine: back up your SaveGames folder, export your SMM profile, and check that SML’s ficsit.app page lists the new game version before you press Launch. If your other games are acting up too, the same framework-first approach applies to Cyberpunk 2077 mods not working after a patch, and to BG3 mods not working once Larian updates the game.

What changed

• Nov 13, 2026 First published.

About the article

JO

Written by Jess Okonkwo

Jess writes about Minecraft, The Sims and survival and indie game mods, plus some of the weekly trending picks. She likes mods that change how a game plays rather than just how it looks.

• Fact-checked by Hollis Tremaine against the sources listed below before publication.
• Published November 13, 2026

Sources (8)

1. Satisfactory Mod Loader – ficsit.app (ficsit.app)
2. SatisfactoryModLoader v3.12.0 release notes (newreleases.io)
3. Releases – satisfactorymodding/SatisfactoryModManager – GitHub (github.com)
4. SatisfactoryModManager v3.0.0 release (github.com)
5. Satisfactory 1.0 finally has mod support, and the revamped mod manager now supports dedicated servers too – PC… (pcgamer.com)
6. Crossplay is now available in Satisfactory! – Patch Notes (questions.satisfactorygame.com)
7. Satisfactory patch 1.2.5.0 – SteamDB (steamdb.info)
8. Patch 1.2.5.0 – Official Satisfactory Wiki (satisfactory.wiki.gg)

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