Swagger UI Displays but I get an “ERROR” indicator

Question

My swagger UI displays and it is showing all of my routes. Everything looks great except there is a big red ERROR indicator on the lower right. When I click it I get:

<

Answer 1

"validatorUrl: null" solution still works in 2020. I didn't have validatorURL in my SwaggerUIBundle but I just added it and the error no longer shows now.

const ui = SwaggerUIBundle({
    url: window.location.href.replace('swagger-ui.html','service/swagger.json'),
    dom_id: '#swagger-ui',
    validatorUrl: null,
    presets: [
      SwaggerUIBundle.presets.apis,
      SwaggerUIStandalonePreset
    ],
    plugins: [
      SwaggerUIBundle.plugins.DownloadUrl
    ],
    layout: "StandaloneLayout"
  })

Answer 2

That's the validator badge. The error is most likely because the on-line validator can't reach the OpenAPI spec on your server (devxxxx.com). I am assuming this server is behind a firewall.

Depending on the version of Swagger UI, you may be able to disable the validator badge. In 2.x, you can simply add validatorUrl: null to the SwaggerUi constructor in index.html. In 3.x, there have been problems disabling the validator badge. For more details search for validatorUrl issues over on GitHub.