How to Set Up a Modpack Server

Modpack servers run curated collections of mods that add new gameplay mechanics, dimensions, items, and more. 3LifeHosting.com offers one-click installs for popular modpacks, but you can also install any modpack manually.

One-Click Modpack Installation

If you ordered a modpack-specific plan (e.g. All the Mods, RLCraft, Pixelmon, SkyFactory), the modpack is pre-installed. Just start your server from the panel and you're ready to go.

To switch to a different modpack after purchase:

1. Stop your server
2. Go to the Startup tab
3. Change the server egg or modpack variable to the desired pack
4. Reinstall the server

Reinstalling wipes existing server files. Create a backup first if you have a world you want to keep.

Manual Modpack Installation

For modpacks not available as a one-click option:

Step 1: Download the Server Pack

Most modpacks provide a server pack download on CurseForge or Modrinth. This is different from the client pack — it contains only the files needed for the server.

Step 2: Upload the Files

1. Download the server pack .zip to your computer
2. In the control panel, go to File Manager
3. Delete existing files in the server directory (back up your world first)
4. Upload the server pack .zip
5. Use the Unarchive button (right-click the zip) to extract the files

Step 3: Configure Startup

1. Go to the Startup tab
2. Set the Server Jar File to match the modpack's jar (e.g. forge-1.20.1-47.2.0.jar)
3. Set the correct Minecraft Version
4. Ensure the Java Version is compatible (most modern modpacks need Java 17+)

Step 4: Allocate Enough RAM

Modpacks are memory-hungry. Minimum recommendations:

Check your plan's RAM allocation in the panel. If the server crashes with OutOfMemoryError, you may need to upgrade.

Step 5: Start and Verify

1. Start the server and watch the console
2. First startup takes longer as Forge/Fabric downloads libraries
3. The server is ready when you see Done! in the console

Players Connecting to a Modpack Server

Players must install the same modpack on their client. The easiest way:

1. Install a mod launcher: CurseForge App, Modrinth App, or ATLauncher
2. Search for the modpack and install it
3. Launch Minecraft through the modpack profile
4. Connect to your server's IP and port

The modpack version on the client must match the server. If players see "Mod rejections" on connect, the versions don't match.

Updating a Modpack

1. Download the new server pack version
2. Back up your world folder and any custom configs
3. Delete the mods/ folder entirely — do not just overwrite. Old mod jars left behind cause version conflicts and crashes
4. Delete all other files except the world/ folder
5. Upload and extract the new server pack
6. Move your world folder back in
7. Start the server — it may need to migrate data on first boot

Important: The most common modpack update failure is skipping step 3. Leftover .jar files from the old version will conflict with the new one. Always delete the entire mods/ folder before extracting the update.

Troubleshooting

Server crashes on startup Check logs/latest.log for the error. Common causes: wrong Java version, insufficient RAM, or a mod conflict.

"Missing mods" error on client connect The client's modpack version doesn't match the server. Both need the exact same version.

Server takes 5+ minutes to start Normal for large modpacks. Forge needs to load hundreds of mods. If it exceeds 10 minutes or times out, check for errors in the log.