How to Install a Modrinth Modpack on a Minecraft Server

Install a Modrinth modpack from the Ametistos catalog by matching its Minecraft version, mod loader, Java version, and memory requirements. This walkthrough uses the Fabric Cobblemon pack as an example.

Check the Modpack Requirements First

Open the modpack page on Modrinth and note its supported Minecraft versions.
Check whether the pack requires Fabric, Forge, or NeoForge.
Review the recommended Java version and server RAM.
Confirm that every player will install the matching client-side modpack version.

The Fabric 1.21.1, Java 21, 4 GB RAM, and 2 CPU values shown below are Cobblemon examples. Use the requirements published for your chosen modpack.

Create a Server with the Correct Minecraft Version

Create a new server, choose a clear name, and select the exact Minecraft release supported by the modpack. A server and client using different versions will usually fail to connect.

Ametistos Minecraft server creator selecting name and Minecraft 1.21.1 for Cobblemon — The Cobblemon example uses Minecraft 1.21.1. Match the version required by your own pack.

Select the Matching Mod Loader

Choose the platform required by the pack. Do not select Fabric for a Forge build, or Forge for a NeoForge build, even when the Minecraft version is the same.

Minecraft server platform selector with Fabric Mods highlighted — Cobblemon is configured with Fabric in this example; select the loader declared by the Modrinth project.

Allocate Enough RAM and CPU

Open Server settings before installation and increase resources when the modpack requires them. More configured RAM consumes credits faster, and the panel updates the estimated play time before you save.

Ametistos server settings configured with Fabric, Minecraft 1.21.1, 4 GB RAM and 2 CPU — The example allocates 4 GB RAM and 2 CPU. Use the pack author's recommendation and expected player count.

Select a Compatible Java Version

Choose the Java runtime required by the Minecraft and modpack release. The example uses Java 21. If the project documentation does not state a Java version, check the loader documentation and the Minecraft release requirements before starting the server.

Ametistos Java version selector with Java 21 selected for a Fabric server — Java must be compatible with the selected Minecraft release, loader, and modpack.

Find and Review the Modrinth Modpack

Open Mods & plugins.
Select Modpacks and the required platform filter.
Search for the project name.
Select Review install on the correct result.
Verify the project, loader, and Minecraft version one more time.

Ametistos Modrinth modpack catalog filtered for Fabric and Cobblemon — Search the Modpacks catalog, apply the correct loader filter, and review the intended project.

Confirm the Required Full Server Reset

Installing a modpack replaces the current installation. The world, plugins, mods, datapacks, and configuration files are deleted. Download anything you need before continuing; the reset cannot be undone.

Ametistos Reset and install modpack confirmation warning — Select Reset and install only after accepting that all current server files will be deleted.

Follow Download and Installation Progress

Open the live console after confirmation. A successful installation downloads the modpack files and starts the selected loader. Large packs can take longer during the first launch while files and the world are prepared.

Minecraft console showing Modrinth modpack files downloading — The console shows the modpack download and loader preparation steps.

Confirm the Modded Server Is Online

Wait for startup completion and the RCON listener. Then connect with a Minecraft client using the identical modpack release. If startup fails, read the first relevant console error and recheck loader, game version, Java, memory, and dependencies.

Minecraft modpack console showing successful startup and RCON listener — Successful startup output and RCON availability indicate that the server is ready for a matching modded client.