Cobblemon ModCobblemon Installation Guide
Choose your platform and follow each step in order. If the game refuses to start, the troubleshooting section below matches common errors to their fixes.
Cobblemon Installation Guide
Step-by-step setup for every platform. Choose your system below and follow the steps in order.
- Install Minecraft Java 1.21.1Open the Minecraft Launcher, create an installation for 1.21.1 and launch it once so the game files exist.
- Install a mod loaderRun the Fabric installer (Client, 1.21.1) or the NeoForge 1.21.1 installer. A new profile appears in the launcher.
- Download the filesGet Cobblemon for your loader plus Fabric API and Fabric Language Kotlin (Fabric) or Kotlin for Forge (NeoForge).
- Open the mods folderPress Win + R, type %appdata%\.minecraft\mods and press Enter. Create the folder if it is missing.
- Drop in the jars and playMove every .jar into the folder, choose the loader profile in the launcher and press Play.
- Install Minecraft Java 1.21.1Launch 1.21.1 once from the Minecraft Launcher, then quit the game.
- Run the loader installerOpen the Fabric or NeoForge installer. If macOS blocks it, right-click and choose Open.
- Download the filesGrab Cobblemon for your loader plus its Kotlin library (and Fabric API on Fabric).
- Open the mods folderIn Finder press Cmd + Shift + G and go to ~/Library/Application Support/minecraft/mods.
- Add the jars and playCopy the jars in, select the loader profile and launch. Apple silicon Macs run it natively.
- Install Minecraft Java 1.21.1Use the official launcher or a trusted alternative like Prism Launcher. Make sure Java 21 is available.
- Create a loader instanceIn Prism, create an instance for 1.21.1 and choose Fabric or NeoForge in the Version tab.
- Add the modsUse the Mods tab to add Cobblemon and its libraries, or copy the jars into ~/.minecraft/mods.
- Set memoryGive the instance 4 GB or more under Settings, Java.
- LaunchStart the instance and check the Mods menu lists Cobblemon.
- Own Java EditionYou need a Minecraft Java Edition account. Bedrock or Pocket Edition cannot run Cobblemon.
- Install a Java launcherUse a trusted Java Edition launcher for Android based on PojavLauncher, from its official source only.
- Create a Fabric 1.21.1 profileInstall Fabric from the launcher, then open that profile's mods folder.
- Add the jarsCopy Cobblemon (Fabric), Fabric API and Fabric Language Kotlin into the mods folder.
- Tune performanceAllocate 3 GB or more, set render distance to 6–8 chunks, then launch.
- Check compatibilityiOS Java launchers depend on JIT support that Apple restricts. Setup varies by iOS version and device.
- Install a Java launcherUse a known Java Edition launcher for iOS from its official source and follow its JIT setup steps.
- Create a Fabric 1.21.1 profileInstall Fabric inside the launcher.
- Add the modsImport Cobblemon, Fabric API and Fabric Language Kotlin into the profile.
- Launch and testExpect lower frame rates. A computer gives a smoother experience if you have one.
Troubleshooting Cobblemon
Common errors, what the log says, and the fix. Most problems come down to versions, loaders or memory.
Game crashes on launch
requires fabric-language-kotlin, which is missing
Add Fabric Language Kotlin (Fabric) or Kotlin for Forge (NeoForge) to your mods folder.
Incompatible Minecraft version
Incompatible mods found! cobblemon requires minecraft 1.21.1
Cobblemon 1.8.x runs on 1.21.1 only. Switch your profile to 1.21.1 or use an older Cobblemon build.
Wrong loader build
Mod file is a Fabric mod, not NeoForge
Delete the jar and download the build that matches your loader.
Old Java version
UnsupportedClassVersionError
Minecraft 1.21.1 needs Java 21. Point your launcher to Java 21.
Lag or out of memory
java.lang.OutOfMemoryError: Java heap space
Allocate 4–6 GB, install Sodium on Fabric and lower render distance.
Add-on breaks after update
Mixin apply failed / NoSuchMethodError
Wait for the add-on to update, or roll back Cobblemon to the last compatible version.
Known issues
After big updates, some add-ons and shader packs lag behind for a few days. Performance mods occasionally need updates too. Check each mod's page before updating a large pack.
Performance tips
Use Sodium on Fabric, keep render distance at 8–12 chunks, avoid allocating more than half your system RAM, and close browser tabs while playing. The crash guide covers more.
Files Ready to Install?
Download Cobblemon and its required library from the official builds.