Fix first: in your settings YAML, change `Viewer.ViewpointY: -100` to `Viewer.ViewpointY: -100.0`. The YAML parser treats the bare integer as the wrong type; the decimal form parses correctly. Commenter-verified.

```text
# failing value
Viewer.ViewpointY: -100
# fixed value
Viewer.ViewpointY: -100.0
```

1. Open the settings YAML you pass to the stereo KITTI example.
2. Change `Viewer.ViewpointY: -100` to `Viewer.ViewpointY: -100.0`.
3. Re-run the example. Expected: the settings parse and the example starts.

When to use: the ORB-SLAM3 stereo KITTI example fails while parsing the settings YAML.

When not to use: tracking or IMU problems at runtime (the settings loaded fine there), or other SLAM systems.

Compatibility: ORB-SLAM3, stereo KITTI example, settings YAML.

Variants:
- "orb slam3 kitti yaml parse error"
- "Viewer.ViewpointY -100"
- "stereo kitti example settings yaml"

Root cause: the settings parser expects a floating-point value for Viewer.ViewpointY and chokes on the bare integer -100.

Edge cases: if the parser complains again, check the other numeric settings for the same bare-integer problem.