Troubleshooting Common Subnautica 2 Mod Problems

Mods not working? Game crashing? This guide covers the most common problems and how to fix them.

First Steps — Always Do These

1. Check the log file — BepInEx\LogOutput.log contains error messages that tell you exactly what went wrong.
2. Read the mod page — the author's description and comments section often has known issues and fixes.
3. Check for updates — the game or the mod may have updated and they need to match.

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Game Crashes on Launch

Cause: Missing dependency

[Error] Plugin X has an unresolved dependency: SomeOtherMod

Fix: Install the missing mod. The log will name it. Check the original mod's page for a "Requirements" or "Dependencies" section.

Cause: Conflicting mods

Two mods that patch the same game method can conflict.

Fix: Disable mods one at a time (move the .dll out of plugins\) until the crash stops — that's your culprit. Check both mods' pages for known conflicts.

Cause: Wrong BepInEx version

Game updated its .NET runtime and the old BepInEx no longer hooks.

Fix: Download the latest BepInEx release and re-extract it over your existing installation. Your plugins folder is unaffected.

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Mod Appears to Load But Does Nothing

Check LogOutput.log — if the mod's name doesn't appear in the log, BepInEx never loaded it.

Common reasons:

• DLL is in the wrong folder (not in plugins\)
• DLL is targeting the wrong .NET runtime
• Mod requires another mod to be loaded first (check dependencies)

If the mod IS listed in the log but still does nothing, it may require in-game configuration. Check for a config\ file or an in-game menu.

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UE4SS Mod Not Working

Mod folder structure is wrong

Each UE4SS Lua mod must have this exact layout:

Mods\
└── ModName\
    ├── Scripts\
    │   └── main.lua   ← entry point must be named this
    └── enabled.txt    ← must exist to activate the mod

If enabled.txt is missing, the mod is disabled even if the folder exists.

Wrong install location

UE4SS goes in Win64\, not the game root. If you installed it in the wrong place, the dwmapi.dll hook won't load.

Syntax error in Lua script

Check the UE4SS log at Win64\ue4ss\Logs\UE4SS.log for Lua errors. A single typo prevents the whole script from running.

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Game Won't Start At All (after adding mods)

Nuclear option — disable all mods:

1. Rename BepInEx\plugins\ to BepInEx\plugins_disabled\.
2. Launch the game — if it works, a plugin is the problem.
3. Re-add plugins one at a time to find the bad one.

For UE4SS: delete enabled.txt from every mod folder to disable all Lua mods at once.

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Saves Are Corrupted or Missing Content

Mods that add new items or mechanics can sometimes cause issues when disabled after a save was made with them active.

Best practice:

• Never disable a content-adding mod mid-playthrough.
• Keep a save backup before enabling new mods (see the Save Backup guide).
• If saves won't load, verify game files on Steam first (right-click game → Properties → Local Files → Verify).

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"Access to path is denied" / Antivirus Blocking

Some antivirus software quarantines winhttp.dll (BepInEx hook) or mod DLLs.

Fix:

1. Check your antivirus quarantine folder.
2. Add the entire Subnautica 2 game folder as an exclusion.
3. Re-download and re-extract BepInEx.

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Steam Deck / Linux (via Proton)

BepInEx works on Linux via Steam Proton with some extra steps:

1. Set the Steam launch option:

   WINEDLLOVERRIDES="winhttp=n,b" %command%
   

2. Use the BepInEx_unix or BepInEx_linux_x64 package if available, otherwise the Windows x64 build works under Proton.
3. UE4SS should work as-is under Proton — test with the standard Windows release first.

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Still Stuck?

• Post in the Forum with your LogOutput.log contents.
• Check the mod's comment section on this site or on Nexus Mods.
• Search the Subnautica 2 Modding Discord for your error message.

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