Expected Behavior
ComfyUI Desktop should start normally and open the UI.
Actual Behavior
ComfyUI Desktop crashes at startup with:
Python process exited with code 3221225477 and signal null
This appears to happen during GPU probing. In my logs, the crash occurs when Python reaches torch.cuda.is_available().
Environment
GPU: AMD Radeon RX 6800 (16 GB VRAM)
Architecture: RDNA2 / gfx1030
OS: Windows 11
ComfyUI Desktop: v0.8.24
PyTorch: 2.9.1+rocmsdk20260116
HIP: 7.2.26024-f6f897bd3d
AMD Adrenalin driver: 26.1.1 (and 26.3.1)
Reproduction
Fresh install of ComfyUI Desktop on Windows.
On startup, Desktop crashes immediately and shows:
Python process exited with code 3221225477 and signal null
I also reproduced the failure directly outside ComfyUI with the bundled Python environment:
..venv\Scripts\python.exe -c "import torch; print(torch.version); print(torch.version.hip); print(torch.cuda.is_available())"
Output stops after:
2.9.1+rocmsdk20260116
7.2.26024-f6f897bd3d
The line for torch.cuda.is_available() is never printed because Python crashes at that point.
Additional Notes
This is a fresh install. ComfyUI has never successfully started on this machine.
Disabling extensions/plugins did not resolve the issue.
Logs suggest the crash is triggered during GPU detection, not during workflow execution.
The Windows exit code 3221225477 suggests a native access violation / hard crash rather than a Python exception.
What I already tested
Fresh install
Updated GPU driver
Disabling optional components/plugins
Direct PyTorch test outside the UI
Logs / Evidence
Relevant behavior:
Desktop crashes immediately at startup
The same crash happens when calling torch.cuda.is_available() manually
Exit code is consistently 3221225477
I can provide the full logs if needed.
Question
Is this a known issue with:
AMD RX 6800 / RDNA2 on Windows Desktop
the current ROCm/PyTorch bundle
or driver compatibility with ComfyUI Desktop 0.8.24?
Any recommended workaround would be appreciated.
Expected Behavior
ComfyUI Desktop should start normally and open the UI.
Actual Behavior
ComfyUI Desktop crashes at startup with:
Python process exited with code 3221225477 and signal null
This appears to happen during GPU probing. In my logs, the crash occurs when Python reaches torch.cuda.is_available().
Environment
GPU: AMD Radeon RX 6800 (16 GB VRAM)
Architecture: RDNA2 / gfx1030
OS: Windows 11
ComfyUI Desktop: v0.8.24
PyTorch: 2.9.1+rocmsdk20260116
HIP: 7.2.26024-f6f897bd3d
AMD Adrenalin driver: 26.1.1 (and 26.3.1)
Reproduction
Fresh install of ComfyUI Desktop on Windows.
On startup, Desktop crashes immediately and shows:
Python process exited with code 3221225477 and signal null
I also reproduced the failure directly outside ComfyUI with the bundled Python environment:
..venv\Scripts\python.exe -c "import torch; print(torch.version); print(torch.version.hip); print(torch.cuda.is_available())"
Output stops after:
2.9.1+rocmsdk20260116
7.2.26024-f6f897bd3d
The line for torch.cuda.is_available() is never printed because Python crashes at that point.
Additional Notes
This is a fresh install. ComfyUI has never successfully started on this machine.
Disabling extensions/plugins did not resolve the issue.
Logs suggest the crash is triggered during GPU detection, not during workflow execution.
The Windows exit code 3221225477 suggests a native access violation / hard crash rather than a Python exception.
What I already tested
Fresh install
Updated GPU driver
Disabling optional components/plugins
Direct PyTorch test outside the UI
Logs / Evidence
Relevant behavior:
Desktop crashes immediately at startup
The same crash happens when calling torch.cuda.is_available() manually
Exit code is consistently 3221225477
I can provide the full logs if needed.
Question
Is this a known issue with:
AMD RX 6800 / RDNA2 on Windows Desktop
the current ROCm/PyTorch bundle
or driver compatibility with ComfyUI Desktop 0.8.24?
Any recommended workaround would be appreciated.