title: DoubleClickSearch conversion API request error
body: <p>I have the following code which uses the Google.Apis.Doubleclicksearch.v2 library and which fails on the last line:</p>
  
  <pre><code>class Program
  {
  
      private const string Account = "&lt;&lt;ID&gt;&gt;@developer.gserviceaccount.com";
      private const string P12Path = @"&lt;&lt;APICert&gt;&gt;.p12";
  
      static void Main(string[] args)
      {
          var certificate = new X509Certificate2(P12Path, "notasecret",
              X509KeyStorageFlags.MachineKeySet | X509KeyStorageFlags.PersistKeySet |
              X509KeyStorageFlags.Exportable);
  
          var credentials = new ServiceAccountCredential(
              new ServiceAccountCredential.Initializer(Account)
              {
                  Scopes = new[] { DoubleclicksearchService.Scope.Doubleclicksearch }
              }.FromCertificate(certificate));
  
          DoubleclicksearchService service = new DoubleclicksearchService(new BaseClientService.Initializer()
          {
              HttpClientInitializer = credentials,
              ApplicationName = "MyApp",
              ApiKey = "&lt;&lt;APIKEY&gt;&gt;"
          });
  
          int isoDate = int.Parse(DateTime.Now.AddDays(-1).ToString("yyyymmdd"));
          var conversionRequest = service.Conversion.Get(&lt;&lt;AgencyID&gt;&gt;,
              &lt;&lt;AdvertiserID&gt;&gt;,
              &lt;&lt;EngineAccountID&gt;&gt;,
              isoDate, 10,
              isoDate, 0);
  
          conversionRequest.Execute();
  
      }
  }
  </code></pre>
  
  <p>The error is: </p>
  
  <blockquote>
    <p>Google.GoogleApiException: 'Google.Apis.Requests.RequestError
    An internal error occurred. Please retry your request at a later time. Details: [Invalid id] [500]</p>
  </blockquote>