# werkzeug.exceptions.NotFound: 404 Not Found: The requested URL was not found on the server

- **ID:** `python/flask-static-file-not-found`
- **Domain:** python
- **Category:** config_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

Flask cannot find a static file because the file is missing or the URL path is incorrect.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.x | active | — | — |

## Workarounds

1. **Place the file in the 'static' folder and use correct URL** (95% success)
   ```
   mkdir static
mv style.css static/
# Access via /static/style.css
   ```
2. **Configure custom static folder** (90% success)
   ```
   app = Flask(__name__, static_folder='assets')
   ```

## Dead Ends

- **Placing static files in the templates folder** — Flask serves static files from a 'static' folder by default. (80% fail)
- **Using absolute path in the URL** — Flask expects relative paths from the static folder. (75% fail)