Stable Diffusion WebUI Forge - Classic/Neo

[JJonnahJameson]

Package

As mentioned here: #1241
I'm getting this error during install process of this specific package: Could not install forge-classic (System.UnauthorizedAccessException: Access to the path is denied.
needless to say, i didn't have this issue with the previous version of Stability Matrix.
Thanks for your hard work guys.

When did the issue occur?

Installing the Package

What GPU / hardware type are you using?

Nvidia RTX 3070 8GB + 32GB of Ram + 12400 i5

What happened?

Could not install forge-classic (System.UnauthorizedAccessException: Access to the path is denied.

Console output

Unpacking resources
Unpacking resources
Cloning into 'D:\SM\Data\Packages\Stable Diffusion WebUI Forge - Classic'...
Download Complete
Using Python 3.11.13 environment at: venv
Resolved 2 packages in 274ms
Prepared 1 package in 0.30ms
Installed 1 package in 10ms

• wheel==0.45.1
  Using Python 3.11.13 environment at: venv
  Resolved 139 packages in 1.92s
  Prepared 139 packages in 264ms
  Installed 139 packages in 2.66s
• absl-py==2.3.1
• addict==2.4.0
• aiohappyeyeballs==2.6.1
• aiohttp==3.12.15
• aiosignal==1.4.0
• albumentations==1.4.3
• antlr4-python3-runtime==4.9.3
• anyio==3.7.1
• attrs==25.3.0
• certifi==2025.8.3
• cffi==2.0.0
• charset-normalizer==3.4.3
• clean-fid==0.1.35
• clip==1.0 (from https://github.com/openai/CLIP/archive/d50d76daa670286dd6cacf3bcd80b5e4823fc8e1.zip)
• colorama==0.4.6
• coloredlogs==15.0.1
• contourpy==1.3.3
• cssselect2==0.8.0
• cycler==0.12.1
• diskcache==5.6.3
• einops==0.8.1
• facexlib==0.3.0
• fastapi==0.114.2
• filelock==3.19.1
• filterpy==1.4.5
• flatbuffers==25.2.10
• fonttools==4.60.0
• frozenlist==1.7.0
• fsspec==2025.9.0
• ftfy==6.3.1
• fvcore==0.1.5.post20221221
• gitdb==4.0.12
• gitpython==3.1.44
• h11==0.12.0
• httpcore==0.15.0
• httpx==0.24.1
• huggingface-hub==0.30.2
• humanfriendly==10.0
• idna==3.10
• imageio==2.37.0
• inflection==0.5.1
• iopath==0.1.10
• jax==0.7.1
• jaxlib==0.7.1
• jinja2==3.1.6
• joblib==1.5.2
• jsonmerge==1.8.0
• jsonschema==4.25.1
• jsonschema-specifications==2025.9.1
• kiwisolver==1.4.9
• kornia==0.6.7
• lark==1.2.2
• lazy-loader==0.4
• lightning==2.5.1
• lightning-utilities==0.15.2
• llvmlite==0.45.0
• lxml==6.0.1
• markdown-it-py==4.0.0
• markupsafe==3.0.2
• matplotlib==3.10.6
• mdurl==0.1.2
• mediapipe==0.10.21
• ml-dtypes==0.5.3
• mpmath==1.3.0
• multidict==6.6.4
• networkx==3.5
• numba==0.62.0
• numpy==1.26.4
• omegaconf==2.2.3
• onnx==1.19.0
• onnxruntime==1.22.1
• open-clip-torch==1.3.0
• opencv-contrib-python==4.11.0.86
• opencv-python==4.8.1.78
• opencv-python-headless==4.11.0.86
• opt-einsum==3.4.0
• packaging==24.2
• piexif==1.1.3
• pillow==11.2.1
• pillow-heif==0.22.0
• platformdirs==4.4.0
• portalocker==3.2.0
• propcache==0.3.2
• protobuf==4.25.7
• psutil==5.9.8
• pycparser==2.23
• pydantic==1.10.22
• pygments==2.19.2
• pyparsing==3.2.4
• pyreadline3==3.5.4
• python-dateutil==2.9.0.post0
• pytorch-lightning==2.5.5
• pywavelets==1.9.0
• pywin32==311
• pyyaml==6.0.2
• referencing==0.36.2
• regex==2025.9.18
• reportlab==4.4.4
• requests==2.32.5
• resize-right==0.0.2
• rich==13.9.4
• rpds-py==0.27.1
• safetensors==0.5.3
• scikit-image==0.21.0
• scikit-learn==1.7.2
• scipy==1.16.2
• sentencepiece==0.2.1
• setuptools==80.9.0
• six==1.17.0
• smmap==5.0.2
• sniffio==1.3.1
• sounddevice==0.5.2
• spandrel==0.4.1
• spandrel-extra-arches==0.2.0
• starlette==0.38.6
• svglib==1.5.1
• sympy==1.14.0
• tabulate==0.9.0
• termcolor==3.1.0
• threadpoolctl==3.6.0
• tifffile==2025.9.20
• timm==1.0.15
• tinycss2==1.4.0
• tokenizers==0.13.3
• torch==2.8.0
• torchdiffeq==0.2.5
• torchmetrics==1.8.2
• torchsde==0.2.6
• torchvision==0.23.0
• tqdm==4.67.1
• trampoline==0.1.2
• transformers==4.30.2
• typing-extensions==4.15.0
• urllib3==2.5.0
• wcwidth==0.2.13
• webencodings==0.5.1
• yacs==0.1.8
• yapf==0.43.0
• yarl==1.20.1
  Using Python 3.11.13 environment at: venv
  Resolved 13 packages in 1.85s
  Prepared 13 packages in 85ms
  Uninstalled 12 packages in 970ms
  Installed 13 packages in 1.03s

• filelock==3.19.1

• filelock==3.13.1

• fsspec==2025.9.0

• fsspec==2024.6.1

• jinja2==3.1.6

• jinja2==3.1.4

• markupsafe==3.0.2

• markupsafe==2.1.5
  ~ mpmath==1.3.0

• networkx==3.5

• networkx==3.3

• numpy==1.26.4

• numpy==2.1.2

• pillow==11.2.1

• pillow==11.0.0

• sympy==1.14.0

• sympy==1.13.3

• torch==2.8.0

• torch==2.8.0+cu128
• torchaudio==2.8.0+cu128

• torchvision==0.23.0

• torchvision==0.23.0+cu128

• typing-extensions==4.15.0

• typing-extensions==4.12.2
  Could not install forge-classic (System.UnauthorizedAccessException: Access to the path is denied.
  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](Dictionary2 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(IProgress1 progress)
  at StabilityMatrix.Core.Models.PackageModification.PackageModificationRunner.ExecuteSteps(IEnumerable`1 steps))

Version

2.15.0

What Operating System are you using?

Windows