# api_version_unsupported

> The API version to pin is older than the oldest supported version.

Source: https://tickwire.io/docs/errors/api_version_unsupported/

HTTP 400.

**Likely cause:** The version is past its sunset, or predates every published version.

**What to do:** Pin one of metadata.supportedVersions. The pin was not changed.

**Retry:** No. The same request gets the same answer; change something first.

Listed under [Requests and validation](https://tickwire.io/docs/errors/#requests-and-validation) in [Errors](https://tickwire.io/docs/errors/). Send the error's `requestId` to support and we can find the request.