# [FAQ] Tool Won't Open — Fixing the "Application Control / DLL load failed" Security Block

## Symptom

When launching the tool (os_bipedPlus / os_fast_ref) in 3ds Max, the following error appears and the window does not open:

```
ImportError: DLL load failed while importing pyarmor_runtime:
An Application Control policy has blocked this file.
```

Characteristics:
- Installation succeeds, but the error only occurs **when launching** the tool.
- It may occur only in a **specific 3ds Max version (e.g., a freshly installed 2027)** while **another version on the same PC (e.g., 2025) works fine**.
- It works perfectly on other people's PCs.

## Conclusion First (You Can Relax)

**This is NOT malware. It is a false positive from a security program.**

Our tool ships its Python code **encrypted (obfuscated)** to protect licensing and code copyright. This is a standard protection method commonly used by commercial paid plugins.

The protection runtime file used for this (`pyarmor_runtime.pyd`) is not separately code-signed, so some Windows security features mistake it for an **"unknown, unfamiliar file"** and block it from loading.

- Therefore, **adding an exception (allow) in your security program immediately fixes it.**
- Why only a specific Max version: it simply reflects the moment this file was first loaded after a **fresh install** of that version. It is not a problem with the tool or the Max version itself.

## Cause (Technical)

| Item | Details |
|------|---------|
| Blocked by | Windows Application Control (Smart App Control / WDAC), or antivirus / EDR / corporate security policy |
| Blocked file | The unsigned protection runtime `pyarmor_runtime.pyd` |
| Why only some PCs | Security policy On/Off and reputation status differ per machine (expected behavior) |

## Solution

### Option A — Add the tool folder to your security program's exceptions (Recommended)

Add the tool's install folder below to the **exceptions (exclusion / allow list)** of your antivirus / security program.

- os_bipedPlus:
  `%LOCALAPPDATA%\Autodesk\3dsMax\<version>\ENU\scripts\os_bipedPlus_package`
- os_fast_ref:
  `%LOCALAPPDATA%\Autodesk\3dsMax\<version>\ENU\scripts\os_fast_ref_package`

> If you don't know the folder path, type `getDir #userScripts` in the 3ds Max **MAXScript Listener (F11)** to print the exact parent path.

After adding the exception, **restart 3ds Max** and launch the tool again.

### Option B — Check Windows Smart App Control (Windows 11)

1. Open **Settings → Privacy & security → Windows Security**
2. Click **App & browser control**
3. Find **Smart App Control**
4. If it is **On / Evaluation**, switch it to **Off**
5. **Reboot the PC** and relaunch 3ds Max

> If this is a corporate/managed PC and you cannot change the setting, ask your IT admin to add the folder from Option A to the security exception list.

## If You Want Extra Peace of Mind

You may upload the files from the excepted folder to [VirusTotal](https://www.virustotal.com/) and scan them yourself. We plan to apply Code Signing in the future to prevent such false positives.


---

## 문의 / Contact / お問い合わせ / 联系

설치·실행 중 문제가 지속되면 언제든지 연락 주세요.
If the problem persists during installation or launch, feel free to contact us anytime.

- **OtakuSolutions 고객지원 / Customer Support**