TagLab GUI does not open on Windows 11 with Python 3.11.9 (no error, silent exit after TagLab.py)

[sandysawh]

Hi, I’m trying to run TagLab on a work Windows 11 laptop and also see the same behaviour on a Dell and a Mac: TagLab.py exits immediately with no GUI and no console error.

Setup (Windows 11)

• Python: 3.11.9 (64‑bit), installed for all users in C:\Program Files\Python311

• TagLab: latest main (TagLab-main.zip from GitHub, 8 April 2026)

• Env:

  cd C:\Users\ss2201550\TagLab
  py -3.11 -m venv taglab-env
  C:\Users\ss2201550\TagLab\taglab-env\Scripts\activate
  cd C:\Users\ss2201550\TagLab\TagLab-main
  python install.py cpu

• install.py cpu completes and installs:

  • torch 2.5.0, torchvision 0.20.0 (CPU build)
  • gdal 3.9.2, rasterio 1.3.11 (from cgohlke geospatial wheels)
  • downloads dextr_corals.pth and deeplab-resnet.pth.tar into models/

• PyQt5 is present:

  python -m pip show PyQt5  # PyQt5 5.15.11

• Torch sees no CUDA (as expected):

  import torch
  print(torch.cuda.is_available())  # False
  print(torch.__version__)          # 2.5.0

Problem

(taglab-env) C:\Users\ss2201550\TagLab\TagLab-main>python TagLab.py

• Returns immediately to the prompt.
• No error or warning printed.
• No TagLab window appears in the taskbar or Alt+Tab.
• With set QT_DEBUG_PLUGINS=1 there is still no output at all.

I previously saw the “Incompatible version between pytorch, cuda and python” and ModuleNotFoundError: osgeo errors before running install.py cpu, but those are now resolved.

Questions

• Is the current main branch expected to work with Python 3.11.x + PyQt5 5.15.11 on Windows 11 using install.py cpu?
• Is there a known issue that makes TagLab.py exit silently on startup?
• Is there a recommended TagLab release tag / Python version I should use for a stable GUI on current Windows/macOS?

Happy to add debug prints to TagLab.py if you can indicate where the startup checks may be exiting.

[maxcorsini]

Dear Sandysawh,

we have another problem similar to your problem on a Windows machine. The versions of the software installed are ok but TagLab exited immediately after launched. We are working to understand exactly what happen to fix this problem.

We are sorry for the inconvenience.

Best regards

[maxcorsini]

Dear Sandysawh,

we have found that, sometime, this problem is caused by missing DLLs . In your case, do you have installed the Microsoft Visual C++ Redistributable ?

Best