Ace Combat 8 UE4SS script mods belong in the active loader’s Mods folder, rather than the game’s Paks folder. For the AC8HOTAS package documented here, the loader sits beside Game/Binaries/Win64/AceCombat8.exe. Choose the author’s fresh-install package only when no loader is already installed; otherwise add the mod to the working runtime and preserve its configuration.
Use these modifications in the author’s documented offline setup. The mods directory links to the actual packages and their individual installation and removal instructions.
Choose the right installation branch
| Current installation | Appropriate route |
|---|---|
| No loader, and you want AC8HOTAS | The author’s full-install package and its INSTALL-FULL instructions |
| UE4SS already works | A mod-only package added to that runtime |
| Loader is present but its origin is unknown | Identify the installed package and back up its configuration before replacing anything |
| Mod requires another loader build | Check that requirement before copying its scripts into the existing installation |
The AC8HOTAS author documents testing the mod-only release with UE4SS v3.0.1 Beta, commit 03dbd5c0, Windows x64. Its full package contains a loader used in development, but the assembled package is explicitly awaiting a fresh-install game test. That is a compatibility snapshot, not a promise for every experimental release.
Locate the runtime before adding a mod
Open Steam’s installed-files browser and find the real game executable under Game/Binaries/Win64. A launcher in the top installation directory is a different file.
For an existing setup, inspect the loader’s own folder layout and configuration. UE4SS supports several installation arrangements, so a second folder named Mods is not necessarily the one in use. The fresh log and loader configuration help identify the active runtime.
Then check the extracted mod’s nesting. For a Lua package, the author may expect a structure such as:
| File | Purpose |
|---|---|
| Mods/ModName/Scripts/main.lua | The mod’s entry script |
| Mods/mods.txt | Enabled-mod entries for that runtime |
| UE4SS-settings.ini | Loader settings |
| UE4SS.log | Startup and loading evidence |
An extra archive folder between Mods and ModName can prevent discovery. Keep the package’s required native libraries, configuration and enabled.txt files where its instructions place them.
Enable the selected mod and verify loading
- Close the game.
- Copy the mod-only folder into the runtime’s active Mods directory.
- Add or update its entry in the existing mods.txt.
- If that setup also maintains mods.json, keep the matching enabled state there.
- Launch through the package’s documented offline path.
- Check the newest log, then test the specific feature in an offline scene.
Do not replace the entire mod list with an example supplied by a new download. Keep a copy of settings and custom bindings before an update.
Fix the symptom you can observe
| Symptom | First check | Useful next evidence |
|---|---|---|
| No fresh UE4SS log | Executable directory and installed loader package | Full loader path and startup error |
| Loader starts, but one mod has no effect | Active Mods path, nesting and enabled entry | That mod’s loading line or error |
| HOTAS loads, but controls remain unassigned | Generated device list and bindings.lua | AC8HOTAS/HOTAS log and the rejected action |
| A feature works until restart | Saved configuration and enabled state | Compare startup logs before and after restart |
| Crash began after an update | The modified setup versus your restored baseline | Game build, loader commit, mod version and crash files |
For AC8HOTAS configuration, edit the detected-device bindings and use its F5 refresh. For a native DLL replacement or a loader change, close and restart the process; a configuration hotkey is not a general DLL-unload command.
A published UE4SS issue reports an AC8 crash with every Lua mod disabled. If that matches your symptoms, disabling scripts alone does not establish a clean baseline: the runtime can still be injected. Restore the recorded loader changes before testing the stock client.
Restore the installation
Close the game, remove the selected mod’s folder and enabled entries, and restore any configuration it replaced. Removing one mod from a shared loader does not require deleting the other installed mods.
To return to the stock client, reverse the original package’s loader and offline-launch changes and restore backed-up files. Keep a list of the files you added: Steam’s file verification should not be treated as proof that every extra third-party file was removed.
Sources and version scope
Installation guidance checked October 15, 2026. This page did not execute a loader or test a game session.
- AC8HOTAS INSTALL: supported loader build and mod-only installation.
- AC8HOTAS INSTALL-FULL: fresh-install layout and package limitations.
- UE4SS installation documentation: runtime directories and log verification.
- UE4SS issue 1450: an attributed crash report, not a confirmed diagnosis of every AC8 crash.