How to Install Mods on an Abiotic Factor Server (Official and Legacy Methods)

The supported way to install mods on an Abiotic Factor server is now the in-game Mod Library. Update the game and dedicated server to Steam version 1.5.0.31459 (build 26092436), subscribe to mods from MODS, enable gameplay mods for the specific saved world, save the selection, and host. Players joining that server can view its mod list and are prompted to download required official mods automatically.

Manual PAK and UE4SS installation is a separate, unsupported path for older unofficial mods. It involves server file uploads, possible client-side installs, and a much higher risk of crashes, desynchronization, or lost mod content. The instructions below separate the official Mod.io workflow from those legacy methods so you can choose the right procedure for your server.

What changed with official mod support?

Deep Field Games added official mod support in version 1.5.0. The developer’s update identifies Steam version 1.5.0.31459 and Steam build ID 26092436; dedicated-server operators must update their server as well as their own game before installing official mods. The official system is integrated into the game menus and uses Mod.io for distribution.

Older guides commonly tell administrators to copy files into a server’s Content/Paks directory or install UE4SS. Those instructions describe unofficial mods from before the integrated system and should not be treated as the supported Mod.io procedure. Use them only when a specific unofficial mod explicitly requires that loader and you have confirmed that it still works with your game build.

Official versus unofficial at a glance

Area	Official Mod.io mods	Legacy unofficial mods
Distribution	In-game Mod Library	Manual download, often from a third-party mod page
Activation	Saved Worlds > MODS	Server file paths, UE4SS configuration, or loader-specific toggles
Joining players	Server mod list and automatic download prompt for required official mods	Players may need to install matching client files themselves
Updates	Version-gated; older official mods are disabled until updated by their creators	Updates can break loaders, scripts, packages, saves, or clients without warning
Support	Documented by the developer	Unsupported by the developer; instructions vary by mod and hosting provider

What do I need before installing mods on a dedicated server?

Prepare the game, server, and world before changing any mod setting. This prevents a common failure in which the client is current but the server is still running an older build.

• Update the Steam game to version 1.5.0.31459, build 26092436, or a later version if the developer has released one.
• Update the dedicated server through your host or installation method before launching it.
• Make a separate backup of the world save and, if possible, player data. Disabling a mod can remove its items or deployables from the save.
• Decide whether each mod is a gameplay mod or a cosmetic mod. They are enabled through different menus.
• Read the individual mod page for dependencies, supported game versions, and whether it is official or unofficial.
• Stop the server before making any manual file changes. Never overwrite packaged game files while the process is running.

The official announcements do not publish a separate headless-server command, configuration-file setting, or CLI sequence for enabling Mod.io mods. If your host presents a panel-specific workflow, follow that provider’s current documentation for starting the updated server, then use the in-game world and mod controls described below.

How do I install official gameplay mods?

Use the following sequence for the supported workflow: MODS → subscribe → Saved Worlds → MODS → enable → SAVE → host. Subscribing downloads a mod to your game; enabling it applies that mod to one saved world.

1. Update the client and dedicated server

1. Launch Steam and update Abiotic Factor to version 1.5.0.31459 (build 26092436), or the current version shown by Steam.
2. Update the dedicated server from your host’s control panel or your normal server-update process.
3. Start the game once after updating so the MODS and Saved Worlds controls are available, then close any old server process before making additional changes.

Running different builds can make a mod appear missing, prevent a world from loading, or cause a player to disconnect. Treat the server build as the first compatibility check whenever a mod stops working.

2. Open the Mod Library

1. At the title screen, select MODS.
2. Use the Mod Library’s search and filter controls to find the mod you want.
3. Open the mod’s detail page and read its description, required dependencies, version information, and any multiplayer notes.

The library is the distribution point for official mods. You do not need to copy a Mod.io package into a server directory.

3. Subscribe to each mod

1. Click SUBSCRIBE on the mod’s detail page.
2. Wait for the download to finish before subscribing to another large dependency.
3. To remove a downloaded mod from your library, return to its page and choose UNSUBSCRIBE.

Subscribing alone does not activate a gameplay mod in an existing world. Activation is a separate save-level choice.

4. Enable the mods for the saved world

1. From the title screen, open Saved Worlds.
2. Select the world that the dedicated server will host.
3. Click that save’s MODS button.
4. Select the installed gameplay mods you want active for this world.
5. Click SAVE to commit the selection.

Repeat this process for every world that needs a different mod set. A mod subscribed in the library is not automatically enabled in every save.

5. Host the world normally

After saving the mod selection, host the world through the normal server flow. There is no documented requirement to add a Mod.io identifier to a server configuration file or launch command. If a headless installation does not expose the world controls, consult the host’s current instructions rather than inventing a command-line parameter.

What happens when someone joins a modded server?

A joining player can see which mods the server has enabled. For required official server mods, the game displays a prompt and downloads them before the join process completes.

• The player should accept the download prompt and allow it to finish before retrying the connection.
• A player who declines, cancels, or has an interrupted download may remain unable to join until the required files are available.
• Because the server advertises its official mod list, administrators do not normally need to send every player a manual download link.
• Players should still keep their game updated; a server mod cannot compensate for a client running an incompatible game build.

This automatic synchronization applies to supported official mods. It does not turn an unofficial PAK or UE4SS installation into an automatically managed package.

How are cosmetic mods installed?

Cosmetic mods use the CUSTOMIZATION area rather than a world’s gameplay-mod list. They are marked Local Only, which means the change affects only the player who installed it.

1. Open the game’s CUSTOMIZATION menu.
2. Install or select the cosmetic mod there.
3. Apply the appearance locally and join the server normally.

Other players will see the default cosmetics unless they also install the same cosmetic mod on their own machines. Cosmetic mods therefore do not belong in a server’s gameplay-mod selection, and enabling one for a world will not distribute it to friends.

What should I do if an official mod is disabled after an update?

Official mods carry their own version information. After a game update, older official mods are automatically disabled until their creators release compatible versions.

Check the version first

• Confirm that the game and dedicated server are on the same current build.
• Open the mod’s library page and look for a newer release or compatibility notice.
• Do not force an old version back into the world simply because it worked before the update.

Recover a world safely

1. Stop the server and copy the world save to a safe backup location.
2. Disable the affected mod in the world’s Saved Worlds > MODS menu.
3. Reload the world only after the selection is saved.
4. If the creator publishes an updated version, subscribe to it and enable that version after confirming its requirements.

Deep Field Games warns that stability is not guaranteed when changing mod selections. Removing a mod can remove the content it supplied, including items and deployables. A backup gives you a way to restore the previous state if the save no longer loads as expected.

Are unofficial PAK mods still usable on a server?

Some older PAK mods may still run, but they are unsupported and must be treated as a separate, experimental installation. Deep Field Games says it cannot provide support for unofficial mods, and nearly all older unofficial mods may break after the official modding update. Verify the mod’s own instructions and supported game version before uploading anything.

Use one unofficial mod at a time, test it on a copy of the world, and keep a complete backup of both the server save and player data. If the server crashes or players desynchronize, remove the newest unofficial mod first.

How do I install an unofficial PAK mod?

This legacy layout applies only when the mod author specifically supplies .pak, .utoc, and .ucas files for a server installation.

1. Stop the dedicated server completely.
2. Extract the mod archive on your computer without renaming its files.
3. Upload the mod’s .pak, .utoc, and .ucas files to AbioticFactor/Content/Paks/ on the server.
4. Leave the existing pakchunk0-WindowsServer and global files alone. Do not replace or rename them.
5. Check that the uploaded filenames and extensions are unchanged.
6. Restart the server and test with a disposable or backed-up world.

Some hosting panels expose the game directory as a different root, but the relative AbioticFactor/Content/Paks/ location is the important part. If your provider uses a custom container path, use its documented mapping rather than guessing.

How do I install UE4SS mods on an Abiotic Factor server?

UE4SS mods require the UE4SS loader and a mod-specific folder structure. They are not installed through the official MODS browser.

1. Stop the server.
2. Enable or install UE4SS in the hosting panel if the provider supplies that option.
3. Upload the mod folder, including its Scripts directory when supplied, to AbioticFactor/Binaries/Win64/ue4ss/Mods/.
4. On hosts that expose the container root, the equivalent path may appear as /home/container/AbioticFactor/Binaries/Win64/ue4ss/Mods/.
5. Activate the mod using the method specified by its author: an enabled.txt file, a loader menu, or a line in mods.txt.
6. For a mod that documents the text-file method, a line can look like ThrowStaminaReduction : 1. Preserve the mod’s exact name and spacing.
7. If the package is a Blueprint mod, check whether its files also belong in Content/Paks/LogicMods/.
8. Restart the server and test the mod before adding another one.

UE4SS layouts differ between releases. A folder that contains scripts but lacks the loader, has the wrong capitalization, or is placed one directory too deep will usually appear as if the mod is not installed.

Do players need the same unofficial mods?

Read the mod description for its intended split: server-only, client-only, or both. A server-only mod may require no client files, while a client-required mod must be installed and matched on every player’s machine.

• Server-only: install it on the server and verify that the author does not require a client component.
• Client-only: each player installs it locally; the server may not need the package.
• Server and client: install compatible versions in both places and keep filenames, loader versions, and dependencies aligned.

Missing or mismatched client files can cause crashes, failed joins, visual errors, or gameplay desynchronization. Do not assume that an unofficial mod will be downloaded automatically just because an official Mod.io mod is.

Why did a mod stop working after the update?

Version changes are the most likely cause, especially for unofficial loaders. Official mods are disabled when their version is no longer accepted; unofficial mods can fail outright because their scripts, package references, or loader hooks no longer match the game.

If the server crashes at startup

1. Stop the server and restore the latest known-good backup if the world was changed.
2. Remove the most recently added unofficial mod or loader component.
3. Start with no unofficial mods and confirm that the unmodded world loads.
4. Reinstall or update one mod at a time, checking its stated game-version support.

If players crash or desynchronize when joining

• Compare the server and every client’s game build.
• Check whether the mod requires a client installation.
• Make sure all clients have the same mod version and dependencies.
• Remove client-only files from the server unless the author explicitly requests them there.

If items disappear after disabling a mod

That behavior can be expected: the developer warns that disabling a mod removes its supplied content from the save, including items and deployables. Restore the backup rather than repeatedly toggling the mod on a live world.

What are the safest operating practices for a modded server?

• Keep a dated backup before subscribing, enabling, disabling, or replacing a mod.
• Use a test world to check major gameplay changes before applying them to a long-running community save.
• Add one unofficial mod at a time so a failure has an identifiable cause.
• Record the game build, mod version, loader version, and enabled-world list after each change.
• Tell players when a mod requires a local installation or a client restart.
• Stop the server before uploading, deleting, or replacing PAK and UE4SS files.
• Remove unofficial mods first when troubleshooting, because the developer does not support them.
• Keep the server and client on compatible game builds; a mod update cannot fix a build mismatch.

Which installation method should I use?

Choose the official Mod.io workflow whenever the mod is available in the in-game library. It offers save-level activation, a visible server mod list, and automatic download prompts for required official server mods.

Your situation	Recommended path	Reason
You want a supported gameplay mod	MODS library, subscribe, then enable it for the saved world	Uses the developer’s current system and version checks
You want a cosmetic change for yourself	CUSTOMIZATION	Cosmetic mods are Local Only
A trusted older mod exists only as PAK files	Manual PAK upload, after a backup	Legacy and unsupported; requires file-level administration
A mod explicitly requires UE4SS	Install UE4SS and follow the author’s folder and activation instructions	Not managed by the official browser
Your host does not expose the world’s MODS control	Ask the host for its current dedicated-server procedure	No official headless CLI/config procedure has been published

Can I switch between official and unofficial mods on the same world?

You can change a world’s enabled official mods, but doing so is not risk-free. Back up first, because disabling a mod removes the content it contributed. Unofficial loaders and packages add another layer of uncertainty, so test changes on a copied world before touching the community’s primary save.

For a clean diagnosis, run the world with only its supported official mods, confirm that players can join, and then add legacy components individually. This separates a world-selection problem from a loader or client-file problem.

Frequently Asked Questions

Can a dedicated server download official mods without anyone opening the game?

The developer’s published instructions do not describe a headless command, config key, or standalone server-side Mod.io procedure. If your host cannot expose the in-game world controls, use the host’s current documentation or support channel rather than relying on an old file-copy guide.

Will a cosmetic mod change what everyone on the server sees?

No. Cosmetic mods are Local Only, so each player must install the same cosmetic locally to see it. They do not become part of the server’s shared gameplay-mod list.

What should I back up before changing a mod?

Copy the world save and player data, and keep the copy outside the live server directory. A backup is particularly important when disabling a mod because its items and deployables can disappear from the save.

Why can my friend join an official modded server but not an unofficial one?

Official server mods provide a mod list and download prompt during the join process. Unofficial PAK and UE4SS mods may require each player to install matching files manually, and a missing client component can cause a crash or desynchronization.