title: Google DFP API ReportService is failing with no notable error message
body: <p>I'm trying to pull a pretty basic report from DFP via API and the PHP library provided by Google, <a href="https://github.com/googleads/googleads-php-lib/" rel="nofollow noreferrer">https://github.com/googleads/googleads-php-lib/</a>. I've tried both creating the query in the UI and fetching that ReportQuery from the API and running it (per <a href="https://developers.google.com/doubleclick-publishers/docs/reporting#retrieving_a_saved_reportquery" rel="nofollow noreferrer">https://developers.google.com/doubleclick-publishers/docs/reporting#retrieving_a_saved_reportquery</a>) as well as creating an ad hoc query. All create the request okay, which seems to imply that the query validates okay. Other API requests I've tested work fine, including fetching a list of line items etc.</p>
  
  <p>The pertinent code is as follows:</p>
  
  <pre><code>$statementBuilder = (new StatementBuilder())
  
  
  -&gt;where('AD_UNIT_NAME like \'prebid_\'');
  
  # Create report query.
  $reportQuery = new ReportQuery();
  $reportQuery-&gt;setDimensions([
    Dimension::AD_UNIT_NAME,
    Dimension::CUSTOM_CRITERIA,
    Dimension::DATE
  ]);
  $reportQuery-&gt;setColumns([
    Column::TOTAL_INVENTORY_LEVEL_IMPRESSIONS,
    Column::TOTAL_INVENTORY_LEVEL_WITHOUT_CPD_AVERAGE_ECPM
  ]);
  $reportQuery-&gt;setStatement($statementBuilder-&gt;toStatement());
  $reportQuery-&gt;setAdUnitView(ReportQueryAdUnitView::TOP_LEVEL);
  $reportQuery-&gt;setDateRangeType(DateRangeType::YESTERDAY);
  
  # Create report job.
  $reportJob = new ReportJob();
  $reportJob-&gt;setReportQuery($reportQuery);
  
  # Run report job.
  $reportJob = $reportService-&gt;runReportJob($reportJob);
  
  # Create report downloader.
  $reportDownloader = new ReportDownloader($reportService, $reportJob-&gt;getId(), POLL_TIME_SECONDS);
  
  # Wait for the report to be ready.
  $reportDownloader-&gt;waitForReportToFinish();
  
  # Change to your file location.
  $filePath = sprintf('%s.csv.gz', tempnam(sys_get_temp_dir(),
      'delivery-report-'));
  
  printf("Downloading report to %s ...\n", $filePath);
  
  # Download the report.
  $reportDownloader-&gt;downloadReport('CSV_DUMP', $filePath);
  </code></pre>
  
  <p>Here's the error message I get from the API:</p>
  
  <pre><code>PHP Fatal error:  Uncaught exception 'UnexpectedValueException' with message 'Cannot download report 1834923393 because it has a status of FAILED.' in ~/test/vendor/googleads/googleads-php-lib/src/Google/AdsApi/Dfp/Util/v201611/ReportDownloader.php:146
  Stack trace:
  #0 ~/test/vendor/googleads/googleads-php-lib/src/Google/AdsApi/Dfp/Util/v201611/ReportDownloader.php(116): Google\AdsApi\Dfp\Util\v201611\ReportDownloader-&gt;getDownloadUrl('CSV_DUMP')
  #1 ~/test/dfp/get_prebid_unit_data.php(85): Google\AdsApi\Dfp\Util\v201611\ReportDownloader-&gt;downloadReport('CSV_DUMP', '/tmp/delivery-r...')
  #2 {main}
    thrown in ~/test/vendor/googleads/googleads-php-lib/src/Google/AdsApi/Dfp/Util/v201611/ReportDownloader.php on line 146
  </code></pre>