As of October 23, 2026, American Truck Simulator is on 1.61 stable, with 1.62 in open beta since October 20, and most broken mods come down to the wrong version, a reversed load order, missing DLC or resource packs, or files in the wrong place. The game.log.txt log in Documents\American Truck Simulator almost always tells you which one it is; if it doesn’t, disabling your mods half at a time finds it in just a few tries. With Mexico maps like Reforma, check their dependencies first.
Shortcut: upload your game.log.txt to the Holymod mod analyzer and it’ll tell you which mod is failing, which ones are for a different version of American Truck Simulator and which dependencies you’re missing. It’s free and the file never leaves your computer.
Quick diagnosis
| Symptom | Most common cause | Fix |
|---|---|---|
| Doesn’t show up in the Mod Manager | Still zipped, inside a subfolder or in a different mod folder | Put the loose .scs files in Documents\American Truck Simulator\mod |
| Grayed out or won’t activate | A DLC the mod declares is missing | Install the DLC it asks for |
| Incompatible warning | Made for a different game version | Use the author’s 1.61 version |
| Crash while loading the map | Outdated map, missing resources or wrong order | Check version, packs and order; look at the log |
| Problems after switching to the 1.62 beta | Mods made for 1.61 | Go back to the stable version under Properties, Betas |
| Save acting weird after removing a mod | Mod data left behind in the profile | Restore your profile backup |
Where game.log.txt is and what to look for
SCS lists these folders for American Truck Simulator on its official forum:
- Windows: Documents\American Truck Simulator (game.log.txt and, after a crash, game.crash.txt).
- Linux and Steam Deck: ~/.local/share/American Truck Simulator.
- macOS: ~/Library/Application Support/American Truck Simulator; crash reports go to ~/Library/Logs/DiagnosticReports.
Open it in Notepad right after the problem happens. Problem lines are tagged <ERROR>; focus on the last ones before the crash and on any .scs file names or map paths that show up. In SCS games, map «sector» errors such as «Inconsistent sector data» usually appear when two maps clash or when one isn’t made for your version. SCS points out that game.crash.txt doesn’t overwrite itself: delete it before you reproduce the crash.
Versions: the number one cause
According to SCS’s modding documentation, authors can set the compatible versions in manifest.sii (compatible_versions). If yours isn’t listed, you can’t use the mod until the author updates it; this restriction doesn’t apply to Workshop mods. After every major update, wait for authors to release their new version. If you’re in a hurry, check under Properties, Betas whether SCS offers a branch with the previous version. And if you switched to the 1.62 beta, remember that maps like Reforma are built for 1.61.
Dependencies: DLC and resource packs
The Mod Manager blocks mods that declare a DLC you don’t own (dlc_dependencies). In ATS this matters a lot for big maps, which often require several state DLCs. On top of that, some maps need other mods to work: Reforma requires the Reforma Mega Resources pack, and to combine it with other maps like Coast to Coast or ProMods you need the Reforma Other Maps Patch, in the version that matches your game. Without those pieces, the map can crash on load or show up with gaps.
Load order
Whatever is on top wins. Small tweaks (economy, UI, graphics) go at the top; big maps go at the bottom; compatibility patches go above the maps they connect. If two mods change the same thing, only the higher one counts. We explain it with examples in the ATS mod load order guide, and each map’s author usually publishes their own order: follow it.
How to find the culprit mod
- Copy the profiles (or steam_profiles) folder so you don’t put your save at risk.
- Test without mods on a new profile. SCS recommends one that has never had mods.
- If it works, enable only half of your mods and test again.
- Keep the half where the problem is and split it again.
- Repeat until a single mod is left. With 30 mods, that’s about five tests.
Careful with maps: you can’t just split them down the middle, because a map with its resource pack and its patch works as a single block. Enable or disable them together.
Other common problems
- OneDrive can move your Documents folder: make sure you’re copying mods into the folder the game actually uses.
- Verify the files in Steam (Properties, Installed Files) if the game fails even without mods.
- Download from the official source. Reuploads often carry old versions that cause crashes.
More American Truck Simulator guides: how to install mods, load order, the best maps and ATS and Mexico.
Frequently asked questions
Why won’t Reforma load in my ATS?
The usual causes are not being on version 1.61, missing Reforma Mega Resources or a DLC it requires, or running it with other maps without the official compatibility patch.
Where is the ATS error log?
In Documents\American Truck Simulator\game.log.txt on Windows. On Linux and Steam Deck, in ~/.local/share/American Truck Simulator.
Can I force a mod marked as incompatible?
Not from inside the game: if your version isn’t on its compatibility list, the Mod Manager won’t let you use it. Wait for the author’s update.
Why does a mod work on one profile but not another?
Each profile has its own mod list and its own mod order. Compare the two lists and the active DLCs.
Does the 1.62 beta break mods?
Many of them, yes, especially maps. To play with mods, stay on 1.61 stable until their authors release the new version.