# Headset Calibration Troubleshooting (Unity)

Fixes for common **AR 51 Headset Calibration** problems, starting with what the wearer sees.

## In the headset

| What you see | What to do |
|---|---|
| The panel says **"Step into the capture area"** | Make sure the AR 51 system is running and sees you — your avatar should appear. Check the headset is on the same network. |
| **"Walk a few steps so the system can find you"** stays | Walk around and turn your head a little. With several people in the room, it needs a few steps to know which one is you. |
| **"Headset tracking lost"** | This is the headset's own tracking: light the room and check the boundary is set. |
| Avatar **shifted to one side or rotated** | Stand still for a second looking ahead, then walk a few steps. |
| The room **slowly turns at the start** | Normal for the first seconds; it settles after a few steps. |
| It **follows the wrong person** | The wearer walks and turns their head. If it persists, call `ResetCalibration()`. |

## In Unity and builds

| What you see | What to do |
|---|---|
| Build stops with **"AR51 SDK project validation failed"** | Select the **AR51.Unity.SDK** object and press **Fix** on each item in the Service Manager inspector. |
| Standalone build **connects, then nothing arrives** | `link.xml` is missing from `Assets` — see [Build it yourself, step 5](/docs/unity-sdk/headset-calibration/build-it-yourself/#5-keep-the-network-code-in-il2cpp-builds). |
| **Nothing lines up at all, no hints** | The `Headset Calibrator` isn't in the scene, or the scene has no camera tagged **MainCamera** — the Console shows a warning. |

See [Tips for the wearer](/docs/unity-sdk/headset-calibration/wearer-tips/) for the do's and don'ts that prevent most of these.