This should be the Error UI

You ended up here because you didn't set the following configuration value:

path/to/kratos/config.yml

selfservice:
  flows:
    error:
      ui_url: http://my-app.com/error

You can set this configuration value using environment variable SELFSERVICE_FLOWS_ERROR_UI_URL as well!

If you don't know what that means, head over to User-Facing Error!