# AssertionError: Blueprint 'auth' is already registered

- **ID:** `python/flask-blueprint-registration-error`
- **Domain:** python
- **Category:** config_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

The same Blueprint object is registered multiple times with the app.

## Version Compatibility

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

## Workarounds

1. **Ensure the blueprint is registered only once.** (95% success)
   ```
   app.register_blueprint(auth_bp)  # Call once
   ```
2. **Create a new Blueprint instance for each registration if needed.** (85% success)
   ```
   auth_bp2 = Blueprint('auth2', __name__)
app.register_blueprint(auth_bp2)
   ```

## Dead Ends

- **Registering the blueprint again with a different name.** — The Blueprint object itself is already registered; a new instance is needed. (80% fail)
- **Ignoring the error and continuing.** — The app will not start correctly. (90% fail)