Install Create Aeronautics on your server

Create Aeronautics expands the Create mod with physics-based contraptions, so players can build airships, planes, drones, hot-air balloons, cars and trucks. The Simulated Team publishes it in one bundled jar that contains three parts: Simulated for assembly, redstone components and tools, Aeronautics for flying contraptions, and Offroad for land vehicles. It needs the Create mod and a library called Sable beside it. This guide installs it on a NeoForge 1.21.1 server.

Checked against Create Aeronautics 1.3.2 with Sable 2.0.6 and Create 6.0.10 on NeoForge 1.21.1, October 2026.

What you need first

Modrinth lists one loader and one Minecraft version for Create Aeronautics: NeoForge on 1.21.1. The 1.3.2 jar asks for NeoForge 21.1.228 or newer, Create 6.0.10 or newer, and Sable from 2.0.0 up to but not including 3.0.0. It has no Forge or Fabric build, and the project page says it has visual issues with Iris Shaders.

If your server is on another loader or version, open JAR Manager under More, choose NeoForge under Server software and 1.21.1 under Minecraft version, then press Apply change. The panel picks Java 21 for you. The switch reinstalls the server and keeps your world, so make a backup in the Backups tab first. Change your Minecraft version or mod loader has the full steps.

Install it

1. Open Mods under Content and keep the Modrinth chip selected in the source chip row at the top of the tab. The Game version filter starts on your server's version.
2. Search for Create Aeronautics and press Install.
3. Modrinth lists Sable and Create as required, so a prompt titled "Needs 2 more add-ons" appears. Press Install all (3).
4. Restart from the Console tab, or press Start if the server is stopped. The install toast says "Restart the server to load them".

Open the Installed view and check that Create Aeronautics, Sable and Create are listed with no Failed to load badge. Install the Create mod covers Create on its own.

Players need it too

Modrinth lists Create Aeronautics and Sable as required on both the client and the server, and the jar marks Create as required for both sides too. Each player installs the same three mods for NeoForge 1.21.1. Join a modded server from your launcher covers the player side, and Fix the mismatched mod channel list error explains a refusal when versions differ.

Using it

Sable's page says it adds sub-levels, which are moving regions of blocks, block entities and entities that stay interactive while assembled, and that you use /sable to assemble, modify and query them. Sable adds no content to survival on its own. Aeronautics and Simulated provide the blocks and tools.

Settings

Sable's jar defines config options, including sub_level_substeps_per_tick, which it describes as how many times the physics simulation is stepped every second, and warns that higher values are more performance intensive. It also defines sub_level_tracking_range, the distance to network sub-levels to players at. Sable sends sub-level movement to players over UDP when it can. The option disable_udp_pipeline turns that off, which its description says can improve compatibility with certain mods and networking setups but gives worse performance and latency. On NeoForge 1.21.1, Sable's server settings, including sub_level_substeps_per_tick, are in sable-server.toml in the config folder, and Sable also writes sable-common.toml there. Nothing for Sable is stored in your world folder. Stop the server before you edit it in the File Manager, then start it again.

Common problems

• The server stops at startup: a version in the chain is wrong. Create must be 6.0.10 or newer and Sable must be 2.x. Check all three in the Installed view.
• Lag with many contraptions: the jar says higher sub_level_substeps_per_tick values are significantly more performance intensive. Why is my server lagging and How much RAM does a Minecraft server need help.
• Other mods break: the Sable page warns that it makes extensive use of mixins and is prone to compatibility issues. Add mods one at a time. Fix mod and plugin errors on Minecraft covers reading the Console log.