Code 404

The `Code 404` error usually indicates that the rendering environment on the server is not available or is not configured correctly. This is commonly caused by remote desktop redirection, missing display output devices, unsupported GPU configuration, or an unsupported operating system version.

## Cause 1: The Desktop Session Was Redirected by Windows Remote Desktop

If you log in to the rendering server by using the built-in Windows Remote Desktop feature, the desktop session may be redirected. This can interfere with the rendering environment used by LarkXR.

### Solution

1. Connect to the rendering server by using a remote management tool such as Sunlogin, TeamViewer, or VNC instead of the built-in Windows Remote Desktop client.
2. Restart **LarkXR Rendering Manager**.
3. If necessary, restart the rendering server.

## Cause 2: No Monitor or Dummy Plug Is Connected to a GeForce or Quadro GPU

On GeForce or Quadro GPUs, the rendering server may require a connected monitor or a display emulator (dummy plug / display spoofer) so that the system can detect an active display output.

### Solution

Connect a monitor or display emulator to the rendering server GPU, then restart the rendering service.

Reference:
[NVIDIA Video Encode and Decode GPU Support Matrix](https://developer.nvidia.com/video-encode-decode-gpu-support-matrix#Encoder)

## Cause 3: Tesla GPU Driver or License Requirements Are Not Met

If the rendering server uses a Tesla-series GPU, the required GRID driver or license configuration may be missing.

### Solution

For public cloud deployment, confirm that the Tesla GPU has the correct GRID driver and licensing setup.

Reference:
[Tesla GPU GRID Driver and License Requirements](https://docs.paraverse.cc/doc/505/)

## Cause 4: The Operating System Version Is Not Supported

Windows 7 is no longer supported for this deployment scenario.

### Solution

Use a supported operating system version, such as:
- Windows 10
- Windows Server 2016 or later

## Recommended Troubleshooting Order

1. Confirm that the server is not being accessed through built-in Windows Remote Desktop.
2. Check whether the GPU has a valid active display output, especially for GeForce or Quadro GPUs.
3. If the server uses a Tesla GPU, verify the GRID driver and license configuration.
4. Confirm that the operating system version is supported.

## Notes

- `Code 404` in this article is related to rendering-server environment readiness, not to an HTTP 404 web error.
- Display detection and desktop session type can directly affect whether the rendering service can initialize correctly.
- If multiple conditions may apply, check them in the order listed above.