# AttributeError: 'NoneType' object has no attribute 'copy_from_bbox'

- **ID:** `python/matplotlib-animation-blit-error`
- **Domain:** python
- **Category:** runtime_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

Using blitting in animation without properly initializing the background, often because the canvas is not fully rendered before the first frame.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.8 | active | — | — |
| 3.9 | active | — | — |

## Workarounds

1. **Initialize the background in the init function** (85% success)
   ```
   def init(): ax.plot([], []); return []; ani = FuncAnimation(fig, update, init_func=init, blit=True)
   ```
2. **Ensure the canvas is drawn before starting animation** (90% success)
   ```
   fig.canvas.draw(); ani = FuncAnimation(fig, update, blit=True)
   ```

## Dead Ends

- **Disabling blit entirely** — This works but may reduce performance; the error is about incorrect setup. (30% fail)
- **Setting blit=False in FuncAnimation** — This avoids the error but doesn't leverage blitting; the root cause remains. (50% fail)