ComfyUI is not installed

[Ivan-750TI]

What happened?

Portable or regular Stability matrix installation, ComfyUI always stops at a step :
Python 3.10.11 download complete and then endless waiting. Windows 10, earlier cofmfi and all models worked fine on SM. At the moment, you can raise the comfi separately. I reinstalled Windows from different boot loaders, it doesn't help. I disabled the antivirus and ran SM with administrator rights.

I used versions of SM from 2.12 to the current 2.15. I added Long Polling, installed c++ redistributable. The system is built on 2 Xeon e5 2686 v4 and Attermiter x99 dual. I can't figure out what to do. SM is very important to me, I use video models that need SageAttention and Triton. Help please.

Steps to reproduce

1. Open SM
2. Install ComfyUI
3. Constant waiting in Python 3.10.11 download complete step

Relevant logs

2026-04-02 20:12:41.4843|INFO|StabilityMatrix.Avalonia.ViewModels.RefreshBadgeViewModel|Running refresh command...
2026-04-02 20:12:42.3794|WARN|StabilityMatrix.Core.Services.SettingsManager|[RelayPropertyFor] LibraryDir not set when saving (FirstLaunchSetupViewModel.SelectedGpu -> Settings.PreferredGpu)
2026-04-02 20:13:43.1310|WARN|StabilityMatrix.Core.Services.SettingsManager|[RelayPropertyFor] LibraryDir not set when saving (MainSettingsViewModel.PreferredGpu -> Settings.PreferredGpu)
2026-04-02 20:13:43.5579|INFO|StabilityMatrix.Avalonia.ViewModels.RefreshBadgeViewModel|Running refresh command...
2026-04-02 20:13:43.5579|INFO|StabilityMatrix.Avalonia.ViewModels.RefreshBadgeViewModel|Running refresh command...
2026-04-02 20:13:46.3003|INFO|StabilityMatrix.Avalonia.ViewModels.RefreshBadgeViewModel|Running refresh command...
2026-04-02 20:13:53.2601|INFO|StabilityMatrix.Avalonia.ViewModels.RefreshBadgeViewModel|Running refresh command...
2026-04-02 20:13:54.9499|DEBUG|StabilityMatrix.Core.Database.LiteDbContext|Database collation is not Ordinal (IgnoreCase), rebuilding...
2026-04-02 20:13:55.0174|INFO|StabilityMatrix.Core.Services.ModelIndexService|Loading models from database...
2026-04-02 20:13:55.0329|DEBUG|StabilityMatrix.Avalonia.Services.InferenceClientManager|Model index changed, reloading shared properties for Inference
2026-04-02 20:13:55.0329|INFO|StabilityMatrix.Core.Services.ModelIndexService|Loaded 0 models from database in 15.88ms
2026-04-02 20:13:55.0329|INFO|StabilityMatrix.Core.Services.ModelIndexService|Refreshing model index...
2026-04-02 20:13:55.0516|INFO|StabilityMatrix.Core.Services.ModelIndexService|Model index refreshed with 0 entries, took 4.81ms (7.69ms db)
2026-04-02 20:13:55.0516|DEBUG|StabilityMatrix.Avalonia.Services.InferenceClientManager|Model index changed, reloading shared properties for Inference
2026-04-02 20:13:55.1120|INFO|StabilityMatrix.Avalonia.ViewModels.MainWindowViewModel|App started (1.36m)
2026-04-02 20:14:11.9497|INFO|StabilityMatrix.Avalonia.Helpers.WindowsPrerequisiteHelper|UV not found at "G:\AI\Assets\uv\uv.exe", downloading...
2026-04-02 20:14:13.3875|DEBUG|StabilityMatrix.Core.Processes.ProcessRunner|Starting process 'G:\AI\Assets\7za.exe' with arguments 't G:\AI\Assets\uv.zip' in working directory ''
2026-04-02 20:14:13.3875|DEBUG|StabilityMatrix.Core.Helper.ProcessTracker|Creating Job Object "SM_ProcessTracker_7868"
2026-04-02 20:14:13.3875|DEBUG|StabilityMatrix.Core.Helper.ProcessTracker|Adding Process "7za" [10608] to Job Object "SM_ProcessTracker_7868"
2026-04-02 20:14:14.4404|INFO|StabilityMatrix.Core.Helper.ArchiveHelper|Finished extracting archive "G:\AI\Assets\uv.zip"
2026-04-02 20:14:14.4464|DEBUG|StabilityMatrix.Core.Processes.ProcessRunner|Starting process 'G:\AI\Assets\uv\uv.exe' with arguments 'python list --managed-python --output-format json'
2026-04-02 20:14:14.5035|DEBUG|StabilityMatrix.Core.Helper.ProcessTracker|Adding Process "uv" [8024] to Job Object "SM_ProcessTracker_7868"
2026-04-02 20:14:35.5810|DEBUG|StabilityMatrix.Core.Processes.ProcessRunner|Starting process 'G:\AI\Assets\uv\uv.exe' with arguments '--version'
2026-04-02 20:14:35.5810|DEBUG|StabilityMatrix.Core.Helper.ProcessTracker|Adding Process "uv" [8396] to Job Object "SM_ProcessTracker_7868"
2026-04-02 20:14:35.6417|DEBUG|StabilityMatrix.Avalonia.Helpers.WindowsPrerequisiteHelper|UV already installed at "G:\AI\Assets\uv\uv.exe"
2026-04-02 20:14:35.6417|INFO|StabilityMatrix.Avalonia.Helpers.WindowsPrerequisiteHelper|Python 3.10.11 not found at "G:\AI\Assets\Python310\python310.dll", downloading...
2026-04-02 20:14:35.6417|INFO|StabilityMatrix.Avalonia.Helpers.WindowsPrerequisiteHelper|Downloading Python 3.10.11 from https://www.python.org/ftp/python/3.10.11/python-3.10.11-embed-amd64.zip to G:\AI\Assets\python-3.10.11-embed-amd64.zip
2026-04-02 20:14:36.6114|DEBUG|StabilityMatrix.Core.Processes.ProcessRunner|Starting process 'G:\AI\Assets\7za.exe' with arguments 'a G:\AI\Assets\Python310\python310.zip venv\ -y'
2026-04-02 20:14:36.6114|DEBUG|StabilityMatrix.Core.Helper.ProcessTracker|Adding Process "7za" [10356] to Job Object "SM_ProcessTracker_7868"
2026-04-02 20:14:36.6954|DEBUG|StabilityMatrix.Core.Processes.ProcessRunner|Starting process 'G:\AI\Assets\7za.exe' with arguments 'x G:\AI\Assets\python-3.10.11-embed-amd64.zip -oG:\AI\Assets\Python310 -y'
2026-04-02 20:14:36.7012|DEBUG|StabilityMatrix.Core.Helper.ProcessTracker|Adding Process "7za" [5728] to Job Object "SM_ProcessTracker_7868"
2026-04-02 20:14:36.9421|INFO|StabilityMatrix.Avalonia.Helpers.WindowsPrerequisiteHelper|Downloading Tkinter for Python 3.10.11
2026-04-02 20:20:14.5248|DEBUG|StabilityMatrix.Core.Processes.ProcessRunner|Opening URL 'https://patreon.com/StabilityMatrix'
2026-04-02 20:40:44.2036|INFO|StabilityMatrix.Avalonia.Models.TagCompletion.CompletionProvider|Downloading default tag source "danbooru.csv" ["b84a879"]

Version

2.15.6

What Operating System are you using?

Windows

[SRStwo]

Do you have to use Python 3.10? I suggest at least going to 3.11, as Phoronix.com found big speed improvements starting with that version.

[Ivan-750TI]

Do you have to use Python 3.10? I suggest at least going to 3.11, as Phoronix.com found big speed improvements starting with that version.

If you select any other version of python during the installation of Comfy, the green check mark remains on version 3.10. And version 3.10 is also being installed.

[Ivan-750TI]

Also, if it matters, some components don't load previews in the image view at all. And I tried to install something else through SM that works with python, and the situation persists.

[SRStwo]

Do you have to use Python 3.10? I suggest at least going to 3.11, as Phoronix.com found big speed improvements starting with that version.

If you select any other version of python during the installation of Comfy, the green check mark remains on version 3.10. And version 3.10 is also being installed.

That must be an issue with Windows. I was using Windows and switched to Kubuntu. I actually prefer OpenSUSE but it was more difficult to get the Nvidia driver going on that and not break it with updates so I switched to Ubuntu (Kubuntu) grudgingly. It's working fine. If I were you, I'd run Stability Matrix and ComfyUI in Kubuntu. Python 3.13 works with ComfyUI using that OS and Stability Matrix.

[Ivan-750TI]

Do you have to use Python 3.10? I suggest at least going to 3.11, as Phoronix.com found big speed improvements starting with that version.

If you select any other version of python during the installation of Comfy, the green check mark remains on version 3.10. And version 3.10 is also being installed.

That must be an issue with Windows. I was using Windows and switched to Kubuntu. I actually prefer OpenSUSE but it was more difficult to get the Nvidia driver going on that and not break it with updates so I switched to Ubuntu (Kubuntu) grudgingly. It's working fine. If I were you, I'd run Stability Matrix and ComfyUI in Kubuntu. Python 3.13 works with ComfyUI using that OS and Stability Matrix.

I'm not that good at these things. A while ago, I tried to set up Docker, but I couldn't figure out the folder mapping structure, and it didn't work out, although I was able to solve some of the issues. After that, I tried Kali Linux, but I couldn't resolve the network driver installation problem. I kept returning to Windows. It's likely that I will have to switch to Linux.

[SRStwo]

Kubuntu is easy to set up, easier than OpenSUSE was (because I installed the Nvidia driver manually on that). It does require that you use the correct Nvidia driver for best performance so you'll have to read a bit to discern which one that is. OpenSUSE is nice because it automatically creates snapshots whenever something significant is installed, like the kernel. However, since I keep all of the AI stuff on a separate drive from my Linux boot drive, even if Linux were to go haywire the AI folders (models, etc.) would be fine. Updating the kernel on OpenSUSE requires fixing the Nvidia driver or it won't boot and you have to manually select the older kernel snapshot at boot. So, Kubuntu seems to be the simplest solution at the moment.

One big advantage of Linux is that, unlike Windows, you can install the OS to an external drive.

[SRStwo]

I recommend submitting a separate bug report about the Python checkmark not working in Windows, too.

[NeuralFault]

Just to clear the confusion about the Python version

The usage of Python 3.10 regardless of what is chosen for the package is because it's SM's embedded Python that it uses for initial environment setup pre-install of the actual package. When it goes into actually setting up the package and the venv it uses the standalone Python that is selected for the package.

And the python versions having a checkmark just shows that the Python version is already downloaded and ready in SM's Data/assets/Python directory, or in this case its the embedded one. It won't have the check if the Python doesn't exist locally yet.

Py 3.10 used to be the only Python used for packages pre-2.15. On windows it was the embedded Python and in Linux/Mac it was a full standalone 3.10 used for packages. The devs kept the embedded Python 3.10 for SM's internal functions. Which you'll also notice that in the packages venv on Windows they'll both have a 3.10 folder AND a folder for the actual Py version for the package in venv/libs. The 3.10 one will just basically have nothing in it and left behind by the aforementioned function.