Environment
- OS: Windows 10
- GPU: Intel Arc A770
- Driver: 32.0.101.8801
- Application: Intel AI Playground (ComfyUI Backend Installer)
Describe the Bug
When attempting to install or initialize the comfyui-backend service, the startup sequence immediately crashes with a Windows fatal exception (access violation) during PyTorch initialization.
The standard error log specifically highlights a failure loading c10.dll with a Windows fatal exception: access violation
File "D:\Apps\AI playground\resources\ComfyUI\.venv\Lib\site-packages\torch\__init__.py", line 268, in _load_dll_libraries
raise err
OSError: [WinError 1114] A dynamic link library (DLL) initialization routine failed. Error loading "D:\Apps\AI playground\resources\ComfyUI\.venv\Lib\site-packages\torch\lib\c10.dll" or one of its dependencies
Expected behavior
ComfyUI backend installs and runs successfully regardless of whether the user has Miniconda or Anaconda installed on their system.
Root Cause
Based on my testing: Miniconda and path variables caused the issue, removing them and doing a clean install fixed my issue.
The issue has two layers, both caused by Miniconda being present on the system PATH.
Layer 1 — Venv creation uses the wrong Python interpreter.
The AI Playground installer resolves python via the system PATH when creating the ComfyUI .venv. If Miniconda's Python appears on PATH before any other Python, the installer uses it as the base interpreter. This bakes Miniconda's Python binary into the venv permanently — confirmed by the venv's ctypes path resolving to C:\Users\<user>\miniconda3\Lib\ctypes\__init__.py rather than a standard CPython path. The venv looks isolated but its interpreter is Miniconda's.
Layer 2 — DLL resolution loads conflicting Intel libraries at runtime.
Miniconda ships its own versions of Intel libraries (libiomp5md.dll, mkl_*.dll, and others) in miniconda3\Library\bin. Because this directory is on the system PATH, Windows' DLL loader finds these global copies before the matching versions inside the .venv. The PyTorch XPU backend expects specific SYCL/Intel runtime versions that were compiled together; loading mismatched versions from Miniconda triggers the access violation during hardware initialization.
Either layer alone can cause the crash. Both are present simultaneously when Miniconda is on PATH.
Diagnostic Steps Performed
The following were attempted during troubleshooting and did not resolve the issue:
- Repairing the ComfyUI install from within AI Playground
- Reinstalling AI Playground
- Installing a different version of AI Playground
- Updating GPU drivers
- Updating the Visual C++ Redistributable
- Manually reinstalling PyTorch XPU into the venv
- Creating a directory junction to eliminate spaces in the install path
- Manually adding DLL directories via
os.add_dll_directory()
The following confirmed the root cause:
- Running
python -c "import sys; print(sys.version)" inside the venv showed 3.12.1 | packaged by Anaconda, Inc. — proving the venv was built with Miniconda's Python rather than a standard CPython build.
- Testing with a non-Anaconda Python 3.10 against the same torch installation produced a different error (WinError 126 on c10_xpu.dll instead of WinError 1114 on c10.dll), suggesting the Anaconda-built interpreter is a contributing factor, though this test was not conclusive due to Python version mismatch.
Workaround
- Uninstall AI Playground completely.
- Open Windows System Environment Variables.
- Edit the system
Path variable and remove all entries pointing to the Miniconda installation. Typically five entries:
C:\Users\<user>\miniconda3C:\Users\<user>\miniconda3\ScriptsC:\Users\<user>\miniconda3\Library\binC:\Users\<user>\miniconda3\Library\mingw-w64\binC:\Users\<user>\miniconda3\Library\usr\bin
- Reboot to clear cached DLL state.
- Reinstall AI Playground and initialize the ComfyUI backend.
Environment
Describe the Bug
When attempting to install or initialize the comfyui-backend service, the startup sequence immediately crashes with a Windows fatal exception (access violation) during PyTorch initialization.
The standard error log specifically highlights a failure loading c10.dll with a Windows fatal exception: access violation
Expected behavior
ComfyUI backend installs and runs successfully regardless of whether the user has Miniconda or Anaconda installed on their system.
Root Cause
Based on my testing: Miniconda and path variables caused the issue, removing them and doing a clean install fixed my issue.
The issue has two layers, both caused by Miniconda being present on the system PATH.
Layer 1 — Venv creation uses the wrong Python interpreter.
The AI Playground installer resolves
pythonvia the system PATH when creating the ComfyUI.venv. If Miniconda's Python appears on PATH before any other Python, the installer uses it as the base interpreter. This bakes Miniconda's Python binary into the venv permanently — confirmed by the venv's ctypes path resolving toC:\Users\<user>\miniconda3\Lib\ctypes\__init__.pyrather than a standard CPython path. The venv looks isolated but its interpreter is Miniconda's.Layer 2 — DLL resolution loads conflicting Intel libraries at runtime.
Miniconda ships its own versions of Intel libraries (
libiomp5md.dll,mkl_*.dll, and others) inminiconda3\Library\bin. Because this directory is on the system PATH, Windows' DLL loader finds these global copies before the matching versions inside the.venv. The PyTorch XPU backend expects specific SYCL/Intel runtime versions that were compiled together; loading mismatched versions from Miniconda triggers the access violation during hardware initialization.Either layer alone can cause the crash. Both are present simultaneously when Miniconda is on PATH.
Diagnostic Steps Performed
The following were attempted during troubleshooting and did not resolve the issue:
os.add_dll_directory()The following confirmed the root cause:
python -c "import sys; print(sys.version)"inside the venv showed3.12.1 | packaged by Anaconda, Inc.— proving the venv was built with Miniconda's Python rather than a standard CPython build.Workaround
Pathvariable and remove all entries pointing to the Miniconda installation. Typically five entries:C:\Users\<user>\miniconda3C:\Users\<user>\miniconda3\ScriptsC:\Users\<user>\miniconda3\Library\binC:\Users\<user>\miniconda3\Library\mingw-w64\binC:\Users\<user>\miniconda3\Library\usr\bin