Install a modpack on your server

What a modpack server actually needs

A modpack is a list of mods plus configs, built for one Minecraft version and one mod loader (Forge, NeoForge, Fabric or Quilt). Your server needs:

• The same modpack version your players have installed. 1.2.0 on the client and 1.1.9 on the server will usually refuse to connect.
• The same loader and loader version the pack was built for.
• Only the server-side files. Client-only mods like shader loaders or HUD tweaks either crash a server or do nothing.
• Enough RAM. Heavy packs start at 6 GB and are more comfortable with 8–12 GB. See how much RAM a Minecraft server needs.

The one-click way

On ShulkerHost you pick a pack from the CurseForge or Modrinth library and we install the correct loader and version for you. You then join with the same pack version in your launcher. That is the whole process — the manual steps below are for everyone else, or for packs that are not in the library.

Manual install: CurseForge packs

1. Open the pack’s page on CurseForge and go to its files.
2. Find the file marked as the server pack for the exact version you want. Most large packs publish one.
3. Download the server pack zip and unpack it on your computer.
4. Read the included readme or start scripts. They tell you which loader version and Java version the pack expects.
5. Stop your server and upload the contents to the server folder via SFTP or your server panel’s file manager.
6. Start the server. On the first start it may run the loader installer, download libraries and stop to ask you to accept the EULA. Set eula=true in eula.txt and start again.

If a pack has no server pack, you can build one: install the loader on the server, then copy the mods, config and (if present) defaultconfigs and kubejs folders from your client instance. Remove the client-only mods.

Manual install: Modrinth packs

Modrinth packs come as .mrpack files. They contain a list of mods to download, not the mods themselves.

1. Check the pack page for the Minecraft version and loader.
2. Install that loader on the server (Fabric, Quilt, Forge or NeoForge server installer).
3. Use a tool that can read .mrpack files to download the server-side mods, or export the pack from a launcher that supports Modrinth and copy the mods and config folders.
4. Upload them to the server, start it, accept the EULA.

Getting players connected

• Everyone installs the exact same pack version in their launcher (CurseForge app, Modrinth App, Prism Launcher and others all work).
• Join with the server address from the multiplayer menu.
• If the game says mods are missing or mismatched, compare the version numbers first. That fixes most cases.

Updating a pack later

1. Back up the world first. Pack updates can remove mods, and blocks from removed mods disappear from the world.
2. Read the pack’s changelog. Some updates say “new world required”.
3. Replace the mods and config folders with the new version. Keep world, server.properties, ops.json and whitelist.json.
4. Tell your players to update at the same time.

Common problems

Symptom	Likely cause
Server crashes on start mentioning a client class	A client-only mod is in mods
“Mismatched mod list” when joining	Client and server pack versions differ
Server runs out of memory at startup	Too little RAM for the pack
Long freeze on first start	Normal — the world and configs are generated once

Crash logs live in crash-reports and logs/latest.log. The first lines usually name the mod that failed.

Next steps

Installing single mods instead of a full pack works the same way — see install mods on a Minecraft server. If you moved an existing modded world, back it up before every pack update.