Instances¶

An instance is the game folder of one profile: its worlds, options, resource packs, screenshots and mods. Instances do not share any of these with each other or with the official launcher's .minecraft folder.

Where instances live¶

Each profile gets a default instance named after the profile's identifier: xol-1.8.9, xol-1.7.10, forge-1.8.9, forge-1.7.10, forge-optimized-1.7.10, optifine-1.8.9, optifine-1.7.10. The instance is created the first time you press Play or Repair for that profile.

The fastest way to get there is Settings ▸ Instance ▸ Open folder, which has buttons for the instance folder, resource packs, screenshots and logs. The launcher only opens folders inside the Xol data folder.

Folder layout¶

instances/xol-1.8.9/
├── instance.json        what Xol installed here (do not edit)
├── options.txt          Minecraft's options; presets merge into this file
├── mods/                the profile's mods, and any you add yourself
├── saves/               your worlds
├── resourcepacks/       your resource packs
├── screenshots/         F2 screenshots
├── crash-reports/       crash reports written by the game
├── libraries/           only in OptiFine profiles: OptiFine.jar, the file you imported
└── xol/
    ├── config.json      client settings: modules, layouts (Xol profiles only)
    ├── xol-settings.json   written by Export in the client's General settings
    └── remote.json      written by the launcher before a Xol profile starts

saves, resourcepacks, screenshots and crash-reports are created by Minecraft itself when it first needs them.

The game log that the launcher keeps for each run is not inside the instance. It is in the data folder's logs folder as game-<date and time>.log. The Logs button opens that folder.

What instance.json is for¶

It records which profile the instance belongs to, the manifest revision it was last prepared with, the preset that was last applied, and the list of files Xol placed in it with their checksums. That list is the basis of the isolation rule below.

What remote.json is for¶

Right before a Xol profile starts, the launcher writes the newest remote configuration it has into xol/remote.json. The format can only list module identifiers to switch off, a short plain-text reason for each, and simple on or off flags. It cannot name a file, a class, an address or an argument. The in-game client does not read this file yet; the reader is on the roadmap.

The isolation rule¶

Xol only ever replaces or removes files that it placed itself. Everything else in an instance is yours.

• When a profile's components change (for example the Xol client moves from 0.1.0 to 0.2.0), the old managed jar is retired and the new one is copied in. Your files are untouched.
• Mods you added are listed under Mods Xol did not install and are never deleted or changed.
• An instance belongs to one profile. Pointing another profile at it is refused: "instance "…" belongs to profile …; clone it or choose another instance".

Clone¶

Settings ▸ Instance ▸ Tools ▸ Clone copies the selected instance under a new name, so you can customise it freely and keep the original as it was.

The copy is made under a temporary name and renamed when it is complete, so a failed clone leaves nothing behind. After cloning, pick the new instance in the list at the top of the Instance tab. The choice is remembered per profile.

Repair¶

Settings ▸ Instance ▸ Tools ▸ Repair runs the same preparation as Play without starting the game. It re-checks every file Xol installed against its checksum and restores any that are missing or changed: game files, libraries, assets, the Java runtime, Forge and the profile's components. Your own files are never touched.

On success: "Repair finished: every managed file is present and matches its checksum." While the game runs: "Close the game before repairing its instance."

What uninstalling keeps¶

Uninstalling the launcher removes the program. It does not remove the data folder, so every instance, world, screenshot and setting stays on your computer.

• On Windows this is a setting of the installer: application data is not deleted on uninstall. The automated build checks that %APPDATA%\Xol\instances survives a silent uninstall.
• On macOS, dragging Xol to the Trash does not touch ~/Library/Application Support/Xol.

To remove everything, see Reset and uninstall.

Backing up¶

Copy the instance folder, or at least its saves folder, while the game is closed. Xol is pre-release software; back up worlds you care about.