Set up a Crackpack 3 server

Crackpack 3 is a Forge modpack for Minecraft 1.12.2 made by darkosto and a team of contributors. It mixes magic and tech, with a redesigned surface and a large cave system. You install it on your server from the Modpacks tab, which uses the pack's own server files.

Checked against Crackpack 3 3.0.11 on Forge 1.12.2-14.23.5.2860, October 2026.

What the pack needs

• Minecraft 1.12.2 with Forge 14.23.5.2860. The server files carry the Forge installer and the panel runs it for you. 1.12.2 runs on Java 8, and the panel sets the Java version from the pack's Minecraft version, so there is nothing to pick.
• Memory. The pack's own README says 4 GB is the recommended minimum and that 2 GB works but is not ideal. Your plan sets the RAM, so see how much RAM a Minecraft server needs and the Minecraft plans before you install.
• Disk space. The server files are a download of about 470 MB, and they unpack to more than that.
• The same pack for every player. Each player installs Crackpack 3 3.0.11 on their own computer, from the pack's CurseForge page or the CurseForge app.

Install the server files

1. Open your server and choose Modpacks under Content in the left rail.
2. In the source chip row at the top of the tab, press CurseForge, then search for Crackpack 3.
3. Press Install on Crackpack 3. The popup says it reinstalls your server with the pack (Forge, Minecraft 1.12.2).
4. Leave Take a backup first ticked. The install clears your old server files and a fresh world is generated on first start, using the pack's world preset, so keep that backup if you might want your current world back. If the popup shows Keep my world, settings and player lists, tick it to keep your own world instead, and your own server.properties is put back over the pack's. If the popup shows a note about your world's Minecraft version in its place, your world is newer than the pack and cannot be kept: the pack starts a fresh world and your old one stays in the backup. If it shows neither, a fresh world replaces yours. Tick Start the server when it's ready if you want the server to start by itself.
5. Press Install and reinstall and wait. The install can take a few minutes.

The pack's own Install and ServerStart scripts, and its settings file, are not used. The panel writes its own launch script and sizes the memory from your plan, so changing your plan's RAM needs no reinstall.

First start

Press Start on the Console tab. If the EULA has not been accepted yet, the panel asks you to accept the Minecraft EULA first. The server is up when the console prints a line ending in For help, type "help" or "?".

The pack's server.properties already sets generator-settings={"Topography-Preset":"Crackpack 3"} for the pack's own world shape. The Config Editor only shows and saves the keys it lists, so that line stays as it is. If you ticked Keep my world, settings and player lists, your own server.properties replaced the pack's, so that line is not there.

Your address is in the left rail under Server address. Connect to your server for the first time covers adding it in Minecraft.

Common problems

• Players can't join with a mod mismatch. Their pack version is not the server's. Have them install 3.0.11.
• A newer client file exists but the server files are older. The pack's own update notes say the server files come out after the client and can be delayed by CurseForge's approval. Stay on the version that has server files.
• The server lags or runs out of memory. The pack is heavy on RAM and CPU. Watch the RAM card on the Console tab, and move to a bigger plan if the RAM card stays full.
• The install stops while unpacking. Your plan's disk may be too small for the pack. Check Disk Analyser, clear space, and install again.
• A bug inside the pack. The pack's team takes reports at https://github.com/DarkPacks/Crackpack-3/issues. Quote the pack version in your report.