Installing a modpack on Minecraft Java

Install a modpack on your Minecraft Java server from the Modpack page in your control panel, and understand why every player needs the exact same pack to join.

3 min read · Updated Sep 24, 2026 · By GuavaHost Team

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 from the Modpack page, and covers the single most important rule: everyone who joins needs the exact same pack.

Install the pack from the Modpack page

Your control panel can pull a modpack straight from Modrinth, CurseForge, Feed the Beast, ATLauncher, Technic or Voidswrath and set it up for you, so you rarely need to upload files by hand.

1. Take a snapshot on the Backups page first, in case you want your current world back.
2. Open your server and click Modpack under Minecraft tools in the server menu.
3. Under Find a modpack, pick the library from the list next to the search box, then search for the pack by name, for example All the Mods.
4. Click Choose on the pack. A window lists its versions. Note the one you pick, because your players will need this same version.
5. Click Install… next to that version.
6. Under Your existing server files, choose Keep them (recommended) to leave your world and settings in place, or Delete everything first for a completely clean install. Deleting cannot be undone, and you have to type DELETE to confirm it.
7. Click Install modpack. If the server is running, it stops. The panel then installs the whole pack, which can take several minutes for a big one, and the page shows its progress.
8. When it says the pack is installed, start the server. The first start is slower than normal while the game generates its files.

Have a server pack as a .zip from somewhere else? Upload it on the Files tab and press Unpack next to it. One-click install only covers the libraries listed above.

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:

1. Tell your players the exact pack name and version you installed on the server.
2. 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.
3. Once their pack matches, they add your server using the IP and port shown at the top of your server page (with a copy button next to it), 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. Check the console log for the exact error. Choosing a Java version lists which Java each Minecraft version needs and how to change it.

A single mod is causing crashes. You can remove a problem mod from the mods folder on 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.

• modpack
• minecraft
• java
• curseforge
• modrinth
• ftb

Host a Minecraft Java server From $3.99/mo, with instant setup and DDoS protection.

Still need help? Our team is online 24/7 to answer questions.

Contact support