Error:  Data structure returned is not convertible in the requested format. Try to call this method with the parameters '&amp;format=original&amp;serialize=1'; you will get the original php data structure serialized. The data structure looks like this: 
 $data = array (
  0 =&gt; 
  array (
    'idcustomreport' =&gt; 1,
    'idsite' =&gt; 0,
    'revision' =&gt; 0,
    'report_type' =&gt; 'table',
    'name' =&gt; 'Keyword Per Country',
    'description' =&gt; '',
    'category' =&gt; 
    array (
      'id' =&gt; 'Referrers_Referrers',
      'name' =&gt; 'Acquisition',
      'order' =&gt; 15,
      'icon' =&gt; 'icon-reporting-referer',
    ),
    'subcategory' =&gt; 
    array (
      'id' =&gt; 'Referrers_SubmenuSearchEngines',
      'name' =&gt; 'Search Engines &amp; Keywords',
      'order' =&gt; 10,
    ),
    'dimensions' =&gt; 
    array (
      0 =&gt; 'UserCountry.Country',
      1 =&gt; 'Referrers.Keyword',
    ),
    'metrics' =&gt; 
    array (
      0 =&gt; 'nb_uniq_referrers_keyword',
    ),
    'segment_filter' =&gt; '',
    'created_date' =&gt; '2021-01-06 09:39:16',
    'updated_date' =&gt; '2021-01-06 09:39:16',
    'status' =&gt; 'active',
    'site' =&gt; 
    array (
      'id' =&gt; 0,
      'name' =&gt; 'All Websites',
    ),
  ),
);