Troubleshooting

The agent cannot see the game. What it can read is mpn.py check-mod, the game's own logs through mpn.py log, and what you report after playing. The order below is the one in the madnesswright skill's references/troubleshooting.md, from the loader of release build 25615280 (2026-10-17). Stop at the first fix.

A mod that does not show or does nothing

1. Wrong build. log shows "mods_allowed": false, because Player.log says GAME INITIALIZED: Release v.... The release build skips the loader, so nothing in Mods is read and no mods.log is written. Back up, switch to releasebeta, relaunch. The -nomods launch option also turns the loader off.
2. Not in the Mods list. The folder must sit directly inside Mods, one level deep, with an info.txt or info.json that parses and has a non-empty Name and Description. Player.log says info.txt fail in <folder> when it does not parse and info.txt contains no data when a field is empty. check-mod catches the last two; it does not check where the folder sits.
3. In the list but not enabled. Gear icon, select, ENABLED, Apply. Once Mods/enabled.txt exists, a new folder starts disabled, and log names the folders missing from it.
4. Enabled, nothing changes. A misspelt Filename or Root makes a new, unused entity or gives no inheritance, with no error. A .txt card without Type or with the wrong case logs TYPE ERROR!. A .json card that is bare, not strict, or under an unknown list name is dropped. mods.log lists > FAILED: <Filename> (<Type>) for each card the game could not convert.
5. Model missing or wrong. ObjRef must be the prefab's name inside the .mobj, the bundle must be in an enabled mod, and it must be built with Unity 2019.2.6f1. mods.log lists > ADDED: <name> (...) from Mod: <mod> for each object it registered and ! ERROR: MadObj named "<name>" already exists! for a clash.
6. Scene missing from the Playground list. The name lacks _PG, the .sobj was built without an Asset Label, or the scene breaks a SceneTools rule (mpn.py scene-lint).
7. Stage dropped. No valid SceneName, or no RequiredCharacters.
8. Assembly mod does nothing. See the log lines on Assets and Harmony.
9. Broke after a game update. Mods from the 1.08 era (Not Enough Madness, swapped DLLs) do not work on the Workshop-era beta. Verify the game files in Steam and use the official route.
10. Still stuck. Post the mods.log lines for your mod in the Modding Discord or the game's Steam discussions.

Reading the logs

All three live in the game's data folder, %USERPROFILE%\AppData\LocalLow\Gibbing Tree\Madness Project Nexus\ on Windows:

• Player.log: Unity's log for the last launch (Player-prev.log is the one before). Its first lines give the engine version (Initialize engine version: 2019.2.6f1), and GAME INITIALIZED: <Release|Beta> v<version> the build.
• Mods/mods.log: the game's mod log, rewritten each time mods are applied. The official Modding Overview calls it mods.txt; the game writes mods.log, and mpn.py accepts either name.
• Mods/enabled.txt: the enabled list. Mods/directories.log records which folder each object came from.

mpn.py log reads them and reports problems: lines that look like errors (error, exception, fail, not found, invalid, missing, contains no data, already exists and a few more). It leaves out lines seen on a clean launch of build 25615280 with no mods, which are not mod problems: Shader is not supported on this GPU, TRANSITION SQUAD FAIL: NO ONE TRANSITIONING, and the Launch Parameters and [FAILED] ...exe lines.

The logs below are stand-ins written for these pages, line for line in the shapes the repository's tests use. On a release-branch launch:

python mpn.py --data-dir game-data log

{
  "data_dir": "game-data",
  "game_version": {
    "status": "Release",
    "version": "1.11.a",
    "mods_allowed": false
  },
  "notes": [
    "The last launch ran a Release build (v1.11.a): the game loads no mods unless this reads Beta (the releasebeta branch). Nothing below is about your mod.",
    "no Mods/mods.log yet: the game writes it when it applies mods, which happens only on a Beta build with -nomods absent"
  ],
  "errors": [],
  "enabled": null,
  "mods_log": null,
  "player_log": {
    "file": "game-data\\Player.log",
    "modified": "2026-10-17T18:30:00",
    "lines": 5,
    "problems": [],
    "problem_count": 0,
    "tail": [
      "Initialize engine version: 2019.2.6f1 (fe82a0e88406)",
      "Launch Parameters (0 found)",
      "ERROR: Shader Shader is not supported on this GPU",
      "GAME INITIALIZED: Release v1.11.a",
      "TRANSITION SQUAD FAIL: NO ONE TRANSITIONING"
    ]
  }
}

Exit code 0.

After switching to releasebeta, with two mods enabled, a third folder left out of enabled.txt, one card the game could not convert, and a mod whose info was empty:

python mpn.py --data-dir game-data log --lines 3

{
  "data_dir": "game-data",
  "game_version": {
    "status": "Beta",
    "version": "2.20.a",
    "mods_allowed": true
  },
  "notes": [
    "Not in enabled.txt, so off at launch: old-mod. Enable in the gear-icon menu and Apply."
  ],
  "errors": [],
  "enabled": {
    "file": "game-data\\Mods\\enabled.txt",
    "enabled": [
      "green-hank",
      "faster-reload"
    ]
  },
  "mods_log": {
    "file": "game-data\\Mods\\mods.log",
    "modified": "2026-10-17T18:30:00",
    "lines": 15,
    "problems": [
      {
        "line": 13,
        "text": " > FAILED: Hank (Character)"
      }
    ],
    "problem_count": 1,
    "tail": [
      " > FAILED: Hank (Character)",
      "",
      "\t=== END OF LOG ==="
    ],
    "loaded": [
      {
        "n": 1,
        "source": "LOCAL",
        "dir": "C:/Users/<you>/AppData/LocalLow/Gibbing Tree/Madness Project Nexus/Mods/faster-reload"
      },
      {
        "n": 2,
        "source": "LOCAL",
        "dir": "C:/Users/<you>/AppData/LocalLow/Gibbing Tree/Madness Project Nexus/Mods/green-hank"
      }
    ],
    "applied_harmony": [
      "com.example.fasterreload"
    ]
  },
  "player_log": {
    "file": "game-data\\Player.log",
    "modified": "2026-10-17T18:30:00",
    "lines": 6,
    "problems": [
      {
        "line": 5,
        "text": "info.txt contains no data"
      }
    ],
    "problem_count": 1,
    "tail": [
      "GAME INITIALIZED: Beta v2.20.a",
      "info.txt contains no data",
      "TRANSITION SQUAD FAIL: NO ONE TRANSITIONING"
    ]
  }
}

Exit code 0.

loaded comes from the > (n) [LOCAL|WORKSHOP] <folder> lines and applied_harmony from the APPLIED HARMONY PATCH: lines. A clean check-mod does not mean the game converted every card: FAILED: Hank (Character) above is the kind of line only the game can write.

With no logs at all:

python mpn.py --data-dir empty-folder log

{
  "data_dir": "empty-folder",
  "game_version": null,
  "notes": [],
  "errors": [
    "no Mods/mods.log or Player.log found; launch the game once with the mod enabled"
  ],
  "enabled": null,
  "mods_log": null,
  "player_log": null
}

Exit code 0.