How GDLauncher detects updates
Each mod in your instance is matched against the addon it came from on CurseForge or Modrinth. GDLauncher periodically checks the addon's release feed for a newer file that targets your instance's Minecraft version and mod loader. If one exists, the Update button appears.
Mods that were dragged into the mods folder manually (rather than installed through the Addons browser) don't have a known source, so GDLauncher can't check them automatically. Reinstalling those through Addons gives you update tracking.
When not to update
Mid-playthrough, in a stable modpack, the safer move is usually to not update individual mods. Modpacks are tested as a complete set; swapping one mod's version can introduce a dependency mismatch with a sibling mod that wasn't updated. The pack author handles the version pinning for you.
Update individual mods when:
- You're running a custom instance you assembled yourself, there's no pack author to do it for you.
- A mod has a known security or stability fix and you specifically want it.
- The pack is unmaintained and you're keeping it limping along yourself.
For a maintained modpack, prefer the Change Modpack Version flow, that updates the whole pack as a tested unit.
Locked instances
Modpack instances are locked by default. The lock prevents accidental edits to the pack-managed mod set, but the per-mod Update button still works for mods you added yourself on top of the pack. To update pack-managed mods, unlock the instance first (Settings → unlock toggle), and at that point, you're maintaining the pack manually.
Dependencies
Many mods depend on libraries (Architectury, Cloth Config, Fabric API, etc.). Dependencies are resolved when you first install a mod, the launcher pulls in anything it needs. Updates don't automatically bump existing libraries, though, so if a newer version of a mod requires a newer version of a library you already have, you'll need to update that library yourself from the Addons tab.
If a mod crashes or warns about a missing/outdated dependency after an update, the addon's page on CurseForge or Modrinth lists what version it needs.
Rolling back
If an update breaks something, you can revert it. Open the Mods tab, click the mod, and use the version dropdown on the mod's detail view to pick the previous release. GDLauncher will swap back to that version.
For a complete rollback to before any updates, the cleanest option is restoring the instance folder from a backup (right-click instance → Open folder, before/after copies).
Restart for changes to take effect
Updated jars load at instance launch. If your game is currently running, the new jar sits on disk but isn't active until the next start. Stop the instance, then click Play again.