hostbuf_file_reader_read failed Fix 2026

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.

1. Identify the failing model from the error log (filename appears before the error)
2. Delete the model from ComfyUI/models/[category]/
3. Re