Install an FTB modpack on a Minecraft server

Feed The Beast (FTB) packs such as Skies 2: Aero install from the Modpacks tab, straight from FTB's own servers, so there is nothing to download to your computer first. An install replaces the server's files with the pack's, so read what it changes before you press the button. The table at the end lists every FTB pack we have a guide for.

Checked against FTB Skies 2: Aero 1.13.0 and 1.14.0 (Minecraft 1.21.1, NeoForge 21.1.250 and 21.1.262) and our installer, October 2026.

Before you start

• Check the pack's RAM. Each pack's page on feed-the-beast.com lists what it needs. Skies 2: Aero asks for at least 6 GB of RAM, recommends 8 GB and runs on Java 21. A server's RAM is fixed by its plan, so compare the two first. How much RAM does my Minecraft server need? explains the sizing, and the Minecraft plans page lists what each plan includes. You do not pick Java yourself, because the panel sets it from the pack's Minecraft version.
• Keep a backup. The install window has Take a backup first ticked by default. Leave it ticked unless you have just made one. If the backup can't start, nothing is changed: the window stays open with "The backup didn't start, so nothing was changed" and the reason, such as every backup slot holding a protected backup. Delete a backup or remove protection from one on the Backups tab, or untick the box.

Find and install the pack

1. Open your server and choose Modpacks under Content in the left rail.
2. Choose the Feed The Beast chip above the search box.
3. Type at least three letters of the pack's name. The tab lists up to 12 matches, each with its Minecraft version and loader.
4. Press Install on the pack. A window titled with the pack's name opens, such as "Install FTB Skies 2: Aero?".
5. Leave the version dropdown on "Newest that fits your server", or pick another build. A second dropdown, which starts on Stable, picks the release channel: Stable lists release builds only, Beta adds beta builds and Alpha lists every build.
6. Decide what happens to your world. With Keep my world, settings and player lists ticked, your world, settings and player lists stay. Unticked, the pack's world replaces yours.
7. Tick Start the server when it's ready if you want the server to boot by itself afterwards. It is off by default. If this server has never accepted Minecraft's EULA, ticking it adds an I agree to the Minecraft EULA box below it, and the install button waits until you tick that too.
8. Press and hold Hold to Install and reinstall for three seconds, until it fills.

Open the Console to follow the install. It prints "Installing the FTB pack. This takes a few minutes." while FTB's own server installer works.

Start the server

If you ticked Start the server when it's ready, it boots by itself when the install finishes. Otherwise press Start. If the server has not accepted Minecraft's EULA yet, the panel asks for it when you press Start.

Settings from server.properties are in Config Editor. To switch on command blocks, for example, find Command blocks under Gameplay, switch it on, press Save changes and restart the server. If the editor says the file does not exist yet, start the server once so it writes one. Skies 2: Aero's server files already switch Allow flight on.

Moving to a newer pack version

When Feed The Beast publishes a newer release for your server's Minecraft version, the pack's card on the Modpacks tab shows Update to followed by that version. Press it: the window that opens has Keep my world, settings and player lists ticked. Leave Take a backup first ticked and hold Update and reinstall. When we tested it, FTB Skies 2: Aero went from 1.13.0 to 1.14.0 with its world kept, and the card then read Up to date. The button offers releases only, not betas.

A pack installed before the panel update of 27 October 2026 with "Newest that fits your server" shows neither Update to nor Up to date, because the panel did not record which release it took, and its Installed button in the search results is grayed out. For one of those, take a backup, press Remove modpack, then install the newer version from the dropdown with Keep my world, settings and player lists ticked.

Remove modpack and the install each take a backup named "Pre-switch backup" and protect it. Only the newest of those stays protected: the install's backup lifts the protection from the one Remove modpack took. A backup you protected yourself keeps its protection, and an install backup protected before 27 October 2026 keeps it until it is a week old. If every backup slot is still protected, the install changes nothing: its window stays open with "The backup didn't start, so nothing was changed" and the reason. Untick Take a backup first for that install: the backup Remove modpack took already holds your world.

If the install fails

A failed install shows an alert titled "The last install didn't finish" with Show install log and Retry install. Read the log first, because a retry reinstalls with the same settings.

• "Couldn't fetch FTB's server installer" means nothing was changed. FTB or our node could not be reached, or FTB has no server installer for that version. Try again in a minute, and if it repeats, pick a different version in the dropdown.
• "FTB's installer couldn't install this pack" means FTB's installer stopped part way. The log names the pack and version it tried.
• If the pack installs but will not start, read the crash report. Find and read a Minecraft server crash report shows where it is.
• A pack that is also on CurseForge can be installed from there instead. Install a CurseForge modpack on your server has the steps.

FTB packs at a glance

Each row shows the pack version we last checked a guide against, and pack names that link have their own guide.