[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)

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 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