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How to install a modpack on your Minecraft Server

Modpacks are pre-built collections of mods, configs and (often) custom worlds. There are two ways to get one onto your EnviroMC server: using the built-in Modpacks installer, or downloading the pack's server pack yourself and uploading it manually.


We strongly advise taking a backup (under the "Backups" tab) before installing a modpack. Installing a modpack will overwrite files, and modpack updates in particular are a common cause of world corruption.



Method 1: Installing via the Modpacks tab

This is by far the easiest method and is what we'd recommend for most users.

Head to the Modpacks tab on your server, under the "Minecraft" section of the sidebar. You'll be shown a browsable, searchable list of modpacks, with a Most recently installed modpack panel at the top showing whatever you last installed on this server.


Use the Provider dropdown in the top left to choose where you want to browse from. We support ATLauncher, CurseForge, Feed The Beast, Modrinth, Technic and Voids Wrath - so between them, essentially every mainstream modpack is available. You can also change the Page Size to show more results per page.


Type the name of the pack you're after into the Search Query box. In this example we've selected the CurseForge provider and searched for "Better MC" to find Better MC [FORGE] BMC4. Once you've found it, click the download icon on the right hand side of its row.


An Install modpack window will open. Use the Modpack Version dropdown to pick which version of the pack you want - the latest is selected by default, and it's generally best to stick with the newest release unless you're specifically matching a version your players already have installed.

There's also a Delete Files toggle. Leave this off if you're updating an existing modpack server and want to keep your world; turn it on for a completely clean install (this deletes everything on your server first and is irreversible). Note the warning shown here - modpack updates can cause world corruption, so take a backup first.

Hit Install modpack.


You'll be shown a Running Installer screen while the panel downloads and unpacks the modpack for you. This can take several minutes for larger packs - BMC4 is close to a gigabyte of mods - so leave it be until it's finished. The installer also sets your startup command and picks the correct Java version for the pack automatically.


Once the install has finished, head to the Console tab and hit Start. If prompted, click I ACCEPT on the Accept Minecraft® EULA pop up and the server will carry on booting.

Modded servers take considerably longer to boot than vanilla ones - as you can see above, the console fills with each mod loading in turn, and it's completely normal for a large pack to take several minutes (sometimes longer) on its first start while it builds its configs and generates the world. Once you see Done (...)! For help, type "help", your modpack server is ready.

Big packs are also memory hungry. If your server crashes partway through mod loading, that's usually a sign it needs more RAM than it currently has assigned.



Method 2: Downloading and uploading the server pack manually

If the pack you want isn't listed in the Modpacks tab, or you need a specific version that isn't offered, you can install it yourself. The key thing here is that you need the pack's server pack, not the normal client download - the client file won't run as a server.

Head to the modpack's page on CurseForge - in this example, Better MC [FORGE] BMC4. Click the Files tab to see every published version of the pack.


Click on the file version you want to open its own page, then scroll down to the Additional Files tab. This is where the server pack lives - in this case BMC4_ServerPack_v60.zip. Click the download button on that row to download it.

If a pack has no server pack listed under Additional Files, the author hasn't published one, and you'll need to use the Modpacks tab method above instead.


Make sure your server is stopped, then head to the Files tab on the panel and hit Upload (or drag and drop the zip straight onto the panel). Large server packs can take a while to upload.

Once uploaded, click the three dots next to the zip and choose Unarchive to extract it. Check whether the pack extracted into the root directory or into a subfolder - if everything landed in a subfolder, move the contents up into the root so that files like mods, config and the Forge/Fabric jar sit directly in /home/container. You can delete the zip once you're done.


Head to Startup and point your startup command at whatever the pack provides. Most modern Forge packs ship a run.sh file, in which case set your startup command to ./run.sh. Older packs will include a Forge jar to run directly instead - see our How to install Forge guide for more detail on both cases.

You'll also want to check Startup > Docker Image matches the Java version the pack expects - for 1.20.1 Forge packs like BMC4, Java 17 or 21 is typical.


Finally, head to the Console tab and hit Start, accepting the EULA pop up if prompted. Give it plenty of time on first boot.


Common issues​

  • Permission denied / Exit code 126 - a very common one when running a .sh file from an extracted pack. Our Exit Code 126: Permission Denied guide covers the fix.
  • Server runs out of memory - large modpacks are memory hungry. If your server crashes during startup or while generating chunks, you may simply need more RAM.
  • Wrong Java version - if the server exits immediately with a class version error, change your Docker Image under Startup.

If you're an EnviroMC customer and you're still having trouble getting a modpack running, please reach out to us via a support ticket and we'll be happy to help.