> For the complete documentation index, see [llms.txt](https://docs.layerlens.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.layerlens.ai/more-in-this-section-9/troubleshooting-1.md).

# Troubleshooting

SDK troubleshooting index — authentication, common issues, error codes.

In-depth troubleshooting guides for the LayerLens Python SDK.

| Topic                                                         | Description                                                              |
| ------------------------------------------------------------- | ------------------------------------------------------------------------ |
| [Authentication](/more-in-this-section-9/authentication-1.md) | API key errors, 401 responses, missing configuration.                    |
| [Common Issues](/more-in-this-section-9/common-issues.md)     | Installation, client init, evaluations, trace upload, timeouts, network. |
| [Error Codes](/more-in-this-section-9/error-codes.md)         | Full exception hierarchy and HTTP status mapping.                        |

For a single-page quick reference, see [Troubleshooting (overview)](/more-in-this-section-9/troubleshooting.md).