Troubleshooting

• The log says fewer than 156 nodes loaded. A module failed to import. The lines above it name the module and the error, and the Environment Guard table shows which package is missing. Reinstall the requirements into ComfyUI's own Python (for the Windows portable build: python_embeded\python.exe -m pip install -r ComfyUI\custom_nodes\radiance\requirements.txt).
• SDR → HDR says "learned recovery: NOT APPLIED". The model is not installed and could not be downloaded (offline, RADIANCE_ALLOW_DOWNLOADS=0, or no write access to models/radiance). The console gives the direct download link; put the file in ComfyUI/models/radiance/. The node still outputs a correct deterministic HDR expansion meanwhile.
• HDR looks clipped or washed out in a normal image preview. Standard preview nodes show values above 1.0 as white. Use the Viewer, or write an EXR / PQ file and check it in an HDR-aware application.
• An EXR will not read or write. Check the Environment Guard table for OpenEXR and OpenImageIO. On Python 3.14 OpenEXR is not installed yet and OpenImageIO is used instead.
• Colours look different after upgrading from ≤ 3.2.0. See Notes & Tips; older versions skipped some colour-space conversions.
• Anything else: open an issue with the startup log (from the Radiance Environment Guard table down) and the node's report or metadata output.