# authorization_server_unreachable

> The MCP endpoint could not reach the Tickwire sign-in service to check the access token.

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

HTTP 503. Nothing reached the broker.

**Likely cause:** A network problem, or the sign-in service is restarting.

**What to do:** Retry after a few seconds. The [status page](https://tickwire.io/status/) shows known incidents.

**Retry:** Yes. Nothing happened (or it was a read), so repeat it, after `Retry-After` when present.

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