Unable to re-install Forge Neo

[RaktajinoCoffee]

Package

Stable Diffusion WebUI Forge - Neo

When did the issue occur?

Installing the Package

What GPU / hardware type are you using?

RTX 3060

What happened?

Forge Neo was working perfectly fine until I ran an update. After the update, I could no longer open up Forge Neo. Stability Matrix kept telling me there's some kind of IOException error. I downgraded to an earlier version of Forge Neo, but that didn't work. Then I uninstalled it (while also ensuring it was removed from Stability Matrix's "packages" folder) and tried to reinstall it, but I kept getting errors that prevented it from successfully going through. I've never had these problems before until now. (On a side note, it seems this is only happening with Forge Neo. As a test, I successfully uninstalled and reinstalled ComfyUI without any issues.)

UPDATE: I updated Stability Matrix to version 2.16.0 and the problem still persists. The console output has been updated below.

Console output

Unpacking resources
Unpacking resources
Cloning into 'D:\StabilityMatrix-win-x64\Data\Packages\Stable Diffusion WebUI Forge - Neo'...
Download Complete
Python 3.13.12 (main, Feb  3 2026, 22:53:26) [MSC v.1944 64 bit (AMD64)]
Version: neo
Installing torch and torchvision
Using Python 3.13.12 environment at: venv
Resolved 13 packages in 1.20s
Downloading pillow (6.8MiB)
Downloading torchvision (8.5MiB)
Downloading sympy (6.0MiB)
Downloading torch (1.8GiB)
Downloading numpy (11.7MiB)
Downloading networkx (2.0MiB)
 Downloaded torchvision
 Downloaded pillow
 Downloaded networkx
 Downloaded numpy
 Downloaded sympy
 Downloaded torch
Prepared 13 packages in 46.41s
Installed 13 packages in 2.26s
 + filelock==3.29.0
 + fsspec==2026.4.0
 + jinja2==3.1.6
 + markupsafe==3.0.3
 + mpmath==1.3.0
 + networkx==3.6.1
 + numpy==2.4.4
 + pillow==12.2.0
 + setuptools==70.2.0
 + sympy==1.14.0
 + torch==2.11.0+cu130
 + torchvision==0.26.0+cu130
 + typing-extensions==4.15.0
Installing packaging
Installing triton
Installing sageattention
Installing flash_attn
Installing nunchaku
Installing gradio
Installing requirements
Installing addict (for ControlNet Preprocessor)
Installing ftfy (for ControlNet Preprocessor)
Installing fvcore (for ControlNet Preprocessor)
Installing mediapipe (for ControlNet Preprocessor)
Installing onnx (for ControlNet Preprocessor)
Installing onnxruntime (for ControlNet Preprocessor)
Installing svglib (for ControlNet Preprocessor)
Installing timm (for ControlNet Preprocessor)
Installing yapf (for ControlNet Preprocessor)
Installing insightface (for ControlNet Preprocessor)
Installing depth_anything (for ControlNet Preprocessor)
Installing depth_anything_v2 (for ControlNet Preprocessor)
Exiting because of --exit argument
Could not install forge-neo (System.IO.IOException: Cannot create a file when that file already exists.
   at System.IO.FileSystem.MoveFile(String sourceFullPath, String destFullPath, Boolean overwrite)
   at System.IO.FileInfo.MoveTo(String destFileName, Boolean overwrite)
   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
--- End of stack trace from previous location ---
   at StabilityMatrix.Core.Models.FileInterfaces.FilePath.MoveToAsync(FilePath destinationFile)
   at StabilityMatrix.Core.Helper.FileTransfers.MoveFileAsync(FilePath sourceFile, FilePath destinationFile, Boolean overwrite, Boolean overwriteIfHashMatches)
   at StabilityMatrix.Core.Helper.FileTransfers.MoveAllFiles(DirectoryPath sourceDir, DirectoryPath destinationDir, Boolean overwrite, Boolean overwriteIfHashMatches)
   at StabilityMatrix.Core.Helper.FileTransfers.MoveAllFilesAndDirectories(DirectoryPath sourceDir, DirectoryPath destinationDir, Boolean overwrite, Boolean overwriteIfHashMatches, Boolean deleteSymlinks)
   at StabilityMatrix.Core.Helper.SharedFolders.CreateOrUpdateLink(DirectoryPath sourceDir, DirectoryPath destinationDir, Boolean overwrite, Boolean recursiveDelete)
   at StabilityMatrix.Core.Helper.SharedFolders.UpdateLinksForPackage[T](Dictionary`2 sharedFolders, DirectoryPath modelsDirectory, DirectoryPath installDirectory, Boolean recursiveDelete)
   at StabilityMatrix.Core.Models.Packages.BaseGitPackage.SetupModelFolders(DirectoryPath installDirectory, SharedFolderMethod sharedFolderMethod)
   at StabilityMatrix.Core.Models.PackageModification.SetupModelFoldersStep.ExecuteAsync(IProgress`1 progress)
   at StabilityMatrix.Core.Models.PackageModification.PackageModificationRunner.ExecuteSteps(IEnumerable`1 steps))

Version

2.16.0

What Operating System are you using?

Windows

[sk2k]

I had the same problem. For me it was the VAE folder in packages/neo/models. I deleted the empty VAE folder and Stability Matrix was then able to start Neo without any problems.

[RaktajinoCoffee]

I had the same problem. For me it was the VAE folder in packages/neo/models. I deleted the empty VAE folder and Stability Matrix was then able to start Neo without any problems.

Thank you, that did the trick! I would have never figured that out and, more importantly, why this issue happened in the first place. One moment, Forge Neo was working perfectly fine, and then all of a sudden, it just stopped. The only major thing I did was updating it when the option came up a few days ago. Not sure why that would have caused any issues, but I guess it goes back to the old saying, "If it ain't broke, don't fix it." Anyway, thanks again! I'll be closing this ticket since the issue is technically resolved. I just hope it doesn't happen again, but if it does, I'll know where to look next time. :)