A modpack is a bundle of mods packaged so they all work together as one, usually from CurseForge, FTB or Modrinth. This guide shows how to install one on your GuavaHost server using the panel installer, and covers the single most important rule: everyone who joins needs the exact same pack.
Install the pack with the panel installer
The panel can pull a modpack straight from CurseForge, FTB or Modrinth and set it up for you, so you rarely need to upload files by hand.
- In the panel, open the Settings tab and look for the reinstall or modpack install option. On many modpack setups you set the pack or its ID as a variable on the Startup tab, then use reinstall to fetch it.
- Choose the source: CurseForge, FTB or Modrinth.
- Search for the pack by name, or paste its project ID or URL if the installer asks for one.
- Pick the pack version you want. Note it down, because your players will need this same version.
- Start the install and wait. Modpacks are large, so this can take several minutes while it downloads and unpacks everything.
- When it finishes, open the Console tab and start the server. The first start is slower than normal while the game generates its files.
Modded servers use more RAM than vanilla. If the server struggles or crashes on start, RAM is the usual reason. See our guide on how much RAM a server needs, and reach out if you think you need more.
Every player needs the same modpack
This is the part people miss. A modpack on the server does not send itself to players. Each person has to install the same pack, at the same version, on their own computer before they can join. If their pack does not match the server, they get kicked with a mismatch error the moment they try to connect.
The easiest way to keep everyone in sync:
- Tell your players the exact pack name and version you installed on the server.
- Have them install that pack through a launcher that supports it, such as the CurseForge app, the FTB app, or a Modrinth-compatible launcher like Prism.
- Once their pack matches, they add your server using the IP and port shown at the top of the server view in the panel, and join as normal.
Troubleshooting
Players get a "mismatched mod list" or similar kick message. Their pack or version does not match the server. Confirm they are on the exact same pack and version number, not just the same pack name.
The server crashes on the first start. Often not enough RAM for a modded server, or a corrupted download. Check the console for an out-of-memory message. If the download looks incomplete, reinstalling the pack usually fixes it.
The install finishes but the server will not start. Some packs need a specific Java version. You can switch Java version on the Startup tab using the Docker image selector. Check the console log for the exact error.
A single mod is causing crashes. You can remove a problem mod from the mods folder in the Files tab, but remember: if you change the server's mod list, every player has to make the same change or they will fail to connect.
Still stuck? Jump into our Discord at discord.gg/GuavaHost and the team will help you out.