If you experience the error message “Unable to contact IdentityServer”, it means that the AdminUI backend cannot successfully communicate with IdentityServer.

To troubleshoot this issue, we recommend working through the following steps.

## Does the OpenID Connect discovery document work?

You can verify that your IdentityServer can start-up and access your database by navigating to the OpenID Connect discovery document in your browser, available on the IdentityServer endpoint: `https://<your-identity-server>/.well-known/openid-configuration`.

### Discovery document does not load

If your discovery document does not load, you may instead see an error page containing details on what went wrong. If you do not see any error details, you will need to [check the IdentityServer logs](../Configuration_and_Integration/Enabling_Logging.md).

### Discovery document loads

If your discovery document does load, then the next step is to determine why IdentityServer denied the request.

## Check the IdentityServer logs

Depending on your IdentityServer setup, IdentityServer will be logging failed incoming requests. To enable logging, check out our [logging documentation](../Configuration_and_Integration/Enabling_Logging.md). If you are using your own IdentityServer, we recommend following the [Microsoft documentation](https://docs.microsoft.com/en-us/aspnet/core/fundamentals/logging/) for logging.

## Check your configuration

If you are not seeing any logged requests made to IdentityServer, it may be that AdminUI is not pointing at your IdentityServer. To confirm that AdminUI is configured correctly, check the AuthorityUrl setting for both the UI and API are the expected value in any web.config (when using IIS/Windows) and appsettings.json files (when using Linux or Kestrel). If you are using an Azure App Service, this can also be set in the App Service’s configuration section.

## Check the AdminUI logs

If you are not seeing any logged requests made to IdentityServer and the configuration looks correct, the next step is to check the [AdminUI (UI website) logs](../Configuration_and_Integration/Enabling_Logging.md). This will cover any issues with connecting to your IdentityServer, including certificate validation.

## Support

If none of these steps work or you are unsure how to fix the error in the logs, please contact us at support@identityserver.com, detailing the issue you see, including any error logs.
