MechFix
Optimizes heavy mod packs and cuts moon loading times. The interior is built one chunk per frame, so MechFix frees up frames while you load and gives them back the moment you land.MechFix
Cuts moon loading times in heavily modded Lethal Company.
If your lobby spends more time staring at the loading screen than actually playing, this is for you.
The problem
In a big modpack, pulling the lever and waiting to land can take over a minute. Nobody is playing during that time — four people are sitting still, waiting.
Why it happens
The interior isn't loaded from disk in one go. It is built piece by piece, one chunk per frame. Every frame that passes places a little more of the dungeon.
That has a consequence most people never think about: your loading time depends on your frame rate while loading. If the game is crawling at a handful of frames per second during the descent, the dungeon is being built at a handful of chunks per second, and the wait stretches out.
So anything stealing frames during that window is directly making everyone wait longer — and during a load, the game is rendering a scene nobody is looking at while doing the heaviest work of the round.
What MechFix does
Everything below happens only while the dungeon is being built, and is reverted the moment it finishes.
Frees up frames during the load
- Temporarily lowers the in-game graphics settings — terrain detail, motion blur, pixel resolution and indirect lighting — and puts every one of them back exactly as you had them once you land. You keep your settings; you just don't pay for them while staring at a loading screen.
- Turns off shadows for the duration of the load, the single biggest rendering cost that can be dropped safely.
- Uncaps the frame rate. With V-Sync on, frames that could have been ready early sit waiting for the monitor instead — and each of those frames was a piece of dungeon that didn't get built.
Removes work the game does for nothing
Lethal Company ships with a surprising amount of leftover debug logging in its own AI code, and the voice chat system adds more. These messages fire many times per second, and every one costs main-thread time to build, format and write to disk. Nobody ever reads them.
MechFix cuts that noise at the source and stops the engine from building a stack trace for each message. Real errors keep their full details — those are the ones worth having when something actually breaks.
Optional: cap the dungeon size
Custom moons often ship with much larger interiors than vanilla ones. MechFix can put a ceiling on that, which reduces both loading time and how long it takes to sweep the building.
This is the only setting that changes how the game plays, so it is clearly separated and easy to turn off.
Why this matters for playing with friends
Everyone waits for the slowest player. Each player builds their own copy of the interior, and the round doesn't move on until every client is done. One machine having a rough time holds the entire lobby hostage.
Graphics settings are local to each player, so MechFix has to be installed on every PC to help the group. If only the host has it, the host loads faster and then waits for everyone else — you gain nothing.
⚠️ If you use the dungeon size cap, every player must set the same value. The interior layout is built from a shared seed and the size setting. If those don't match, players end up in different layouts. The rest of the settings are harmless if they differ between players.
Why this matters for large modpacks
The more mods you run, the more chatter goes through the logging pipeline every single frame — and all of it lands on the same main thread that is trying to build your dungeon. A modpack doesn't just add content; it adds constant background cost during the exact moment you can least afford it.
MechFix targets that overhead specifically, so the cost of running a big modpack stops falling on your loading screen.
Why this matters for moon packs
Custom moons are where this hurts most. Many of them ship interiors far larger than anything in the base game, and larger interiors mean more pieces to build, which means more frames, which means a longer wait — and a longer walk once you're inside.
If your modpack is mostly moons, this is the mod that makes them practical to actually play through.
What MechFix does not touch
- Gameplay. No changes to loot, enemies, pathfinding or difficulty.
- Your settings. Graphics are restored exactly as you had them when the load ends. Nothing is saved over your preferences.
- Your ability to debug. Real errors keep their stack traces.
Configuration
Everything can be adjusted or turned off individually in
BepInEx/config/Mechavala.mechfix.cfg — each option is documented in the file itself. The
defaults are what most lobbies will want.
Compatibility
Lethal Company v81, BepInEx 5. No content mods required, though it is built for modpacks that use them. Game internals are resolved by name at runtime, so a future game update is reported in the log rather than preventing the mod from loading.
