OpenCut 1.55.1 Windows — backend fails health check with WinError 206 in torch _load_dll_libraries()

[charlesmumford-alt]

What are you trying to do?

Environment:

The exception is:

FileNotFoundError: [WinError 206] The filename or extension is too long

This appears misleading. The path is only 42 characters and the directory exists. It contains 9 DLLs, including torch_cpu.dll (~306 MB).

A normal Python 3.13.15 process can successfully execute:

os.add_dll_directory(r"C:\Users\charl.opencut\packages\torch\lib")

We also tested repeated registrations of that same 42-character path. In a clean Python process, Windows began returning WinError 206 at approximately registration 763. This suggests that OpenCut's frozen process may be accumulating a very large number of DLL-directory registrations before Torch is imported.

The OpenCut executable is PyInstaller-based. _internal contains approximately 355 native .dll/.pyd/.zip files, including 264 .pyd files.

The bundled server also prints:

System site-packages: added 2 paths from C:\Users\charl\AppData\Local\Programs\Python\Python313\python.EXE

OpenCut's user package Torch is:

PyTorch 2.14.0+cpu

so it is CPU-only, although the machine has an RTX 3080 Ti. This may be a separate packaging/deployment issue.

Hypothesis: one or more OpenCut dependencies/runtime hooks repeatedly call os.add_dll_directory() during startup, eventually exhausting the Windows process's DLL-directory registration resources. Torch happens to be the import at which the failure becomes visible.

Could you check the 1.55.1 Windows packaging/startup code for repeated os.add_dll_directory() calls, particularly runtime hooks and the interaction between the PyInstaller environment and the added system/user site-packages?

What have you tried?

No response

Version and platform

1.55.1 on Windows 10 Pro