This article was originally published on runaihome.com
hostbuf_file_reader_read Error in ComfyUI
The hostbuf_file_reader_read failed error indicates ComfyUI cannot read a model file into memory. This occurs when the file allocation buffer (hostbuf) encounters corrupted data, insufficient system RAM, or permission-denied scenarios during model loading. The error typically appears after upgrading ComfyUI or installing new custom nodes that load incompatible model formats.
Fix 1: Clear ComfyUI Cache and Temp Files
Corrupted cached files often trigger this error after partial downloads or interrupted model loads.
# Navigate to ComfyUI directory
cd /path/to/ComfyUI
# Stop ComfyUI if running
# Windows: Ctrl+C in terminal
# Linux/Mac: pkill -f "python main.py"
# Delete cache directory
rm -rf ~/.cache/ComfyUI # Linux/Mac
# or
rmdir /q/s %USERPROFILE%\.cache\ComfyUI # Windows
# Delete temp folder within ComfyUI
rm -rf /path/to/ComfyUI/temp
# Restart ComfyUI
python main.py
Re-download models that fail to load after clearing cache.
Fix 2: Reinstall Affected Models
Corrupted model files cause hostbuf_file_reader_read failures during buffer allocation.
- Identify the failing model from the error log (filename appears before the error)
- Delete the model from
ComfyUI/models/[category]/ - Re
