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AntonIT99 edited this page Sep 25, 2026 · 2 revisions

Packs Manager

https://drive.google.com/file/d/1DtfY9VI1buBF2DEbcp3vFmibzVp04SQe/view?usp=sharing

The Flan's Mod Ultimate Packs Manager is an optional companion mod for Flan's Mod Ultimate 2.0. It lets authors distribute legacy content packs inside a normal mod jar and installs those bundled packs into the content-pack folder used by the main mod.

Use this page if you installed a second mod file named like "Flan's Mod Ultimate Packs Manager" or flansmodultimate_packs_manager and want to understand what it does or how to build a bundle of your own.

What It Does

On startup, the Packs Manager:

  • finds the content-pack folder used by Flan's Mod Ultimate;
  • resolves the bundled packs version stored inside the Packs Manager jar;
  • extracts the bundled packs into that folder when the resolved packs version is newer than the last extracted version;
  • writes a small hidden JSON state file in the game directory so the main mod knows when extraction is complete;
  • protects existing non-empty folders by moving them to a backup folder when needed.

The Packs Manager does not replace the main Flan's Mod Ultimate mod. It provides and manages ready-to-use content packs for it.

Installation

Install both mods in your mods folder:

mods/
  Flan's Mod Ultimate 2.0.jar
  [1.20.1] Flan's Mod Ultimate Packs Manager-1.0.jar

Start the game or server once. The Packs Manager will create or update the content-pack folder during startup. After that, the main mod loads the extracted packs like normal content packs.

For multiplayer, install the Packs Manager on the server and on every client that joins the server. This keeps gameplay content, models, textures, and sounds matched.

Where Packs Are Extracted

By default, packs are extracted to:

.minecraft/flan/

If you changed the content-pack path in config/flansmodultimate-content-loading.toml, the Packs Manager uses that same path. This means the automatic extraction follows the same folder that the main mod reads from.

For more information about content loading settings, see Mod Config.

First Startup

If the content-pack folder does not exist, the Packs Manager creates it.

If the folder exists but is empty, the Packs Manager extracts the bundled packs into it.

If the folder already contains packs and the extraction state does not prove that the current bundled packs version was already extracted to this exact folder, the Packs Manager assumes the folder may contain user-managed or outdated content. It moves the existing folder to a backup first, then creates a fresh folder for the bundled packs.

The backup is named like:

flan_backup_2026-06-11_18-30-00

Extraction State

The Packs Manager stores extraction status in:

.minecraft/.flansmod_packs_extraction_state.json

The file is in the game directory, not inside the flan/ folder. It is internal metadata used for startup coordination between the Packs Manager and the main mod.

The state records:

  • the extraction protocol version;
  • whether extraction is resolving, complete, or failed;
  • the currently resolved bundled packs version;
  • the last successfully extracted bundled packs version;
  • the exact content-pack folder path used for extraction;
  • an update timestamp;
  • an error message when extraction failed.

The main mod waits for this state file to report complete before loading content packs. If extraction reports failed, or if the state protocol is unsupported, the main mod stops waiting and logs the problem.

Updating Bundled Packs

The extracted pack refresh is controlled by the bundled packs version, not by the Packs Manager jar version. That version is stored inside the Packs Manager jar at:

flansmodultimate_packs_manager/bundled_packs_version.txt

If the resolved bundled packs version is higher than the last extracted version, the Packs Manager extracts the bundled packs again. If the content-pack folder already contains files, the old folder is moved to a backup before the new bundled packs are extracted.

The backup is named like:

flan_backup_2026-06-11_18-30-00

This prevents older extracted packs from being mixed with newer ones.

If Packs Are Already Installed

If the extraction state says the current content-pack folder already has the current or newer bundled packs version, extraction is skipped. This avoids rewriting the same packs every time the game starts.

If you want the Packs Manager to install a clean copy again, remove or rename the current content-pack folder and remove .minecraft/.flansmod_packs_extraction_state.json before starting the game. Keep a backup if you made manual edits.

Backups

Backup folders are created next to the normal content-pack folder. They are not loaded by the mod unless you manually move or copy content from them back into the active content-pack folder.

Use backups to recover manually installed packs or compare what changed after a Packs Manager update.

Custom Content Packs

You can still install your own content packs manually. Put them in the content-pack folder used by the main mod.

If you also use the Packs Manager, avoid editing the extracted bundled packs directly. For balance changes, prefer the Category System. For individual content-pack parameters, see Config Reference.

Troubleshooting

The bundled packs did not appear

Check that the Packs Manager is installed in the mods folder together with the main mod, then restart the game or server.

Also check whether you changed the content-pack path in config/flansmodultimate-content-loading.toml. The packs may have been extracted to that custom folder instead of .minecraft/flan/.

My old packs disappeared

Look for a folder named flan_backup_... next to the active content-pack folder. The Packs Manager moves non-empty folders there when the extraction state does not match the current bundled packs version and content-pack folder path.

A server says content is missing

Make sure the same Flan's Mod Ultimate version, Packs Manager version, and content packs are installed on the server and on every client.

Building a Custom Packs Manager Jar

Put the content packs you want to distribute in the development runtime's run/flan directory, then run:

.\gradlew.bat packsManagerJar

The build bundles those packs into the jar's flan/ directory and writes the Packs Manager jar to build/libs/. Increment src/packsmanager/resources/flansmodultimate_packs_manager/bundled_packs_version.txt whenever an update should replace a previously extracted bundle.

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