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; 1,
    'revision' =&gt; 0,
    'report_type' =&gt; 'table',
    'name' =&gt; 'Pages by New/Returning visitor',
    'description' =&gt; '',
    'category' =&gt; 
    array (
      'id' =&gt; 'CustomReports_CustomReports',
      'name' =&gt; 'Custom Reports',
      'order' =&gt; 65,
      'icon' =&gt; 'icon-business',
    ),
    'subcategory' =&gt; NULL,
    'dimensions' =&gt; 
    array (
      0 =&gt; 'CoreHome.VisitorReturning',
      1 =&gt; 'Actions.PageTitle',
    ),
    'metrics' =&gt; 
    array (
      0 =&gt; 'nb_uniq_visitors',
      1 =&gt; 'nb_visits',
      2 =&gt; 'pageviews',
    ),
    'segment_filter' =&gt; '',
    'created_date' =&gt; '2017-10-20 02:31:50',
    'updated_date' =&gt; '2017-10-20 02:31:50',
    'status' =&gt; 'active',
    'site' =&gt; 
    array (
      'id' =&gt; 1,
      'name' =&gt; 'Demo Site',
    ),
  ),
  1 =&gt; 
  array (
    'idcustomreport' =&gt; 2,
    'idsite' =&gt; 1,
    'revision' =&gt; 0,
    'report_type' =&gt; 'table',
    'name' =&gt; 'Bali pages, breakdown new/returning',
    'description' =&gt; '',
    'category' =&gt; 
    array (
      'id' =&gt; 'CustomReports_CustomReports',
      'name' =&gt; 'Custom Reports',
      'order' =&gt; 65,
      'icon' =&gt; 'icon-business',
    ),
    'subcategory' =&gt; NULL,
    'dimensions' =&gt; 
    array (
      0 =&gt; 'Actions.PageTitle',
      1 =&gt; 'CoreHome.VisitorReturning',
    ),
    'metrics' =&gt; 
    array (
      0 =&gt; 'nb_uniq_visitors',
      1 =&gt; 'pageviews',
      2 =&gt; 'nb_visits',
    ),
    'segment_filter' =&gt; 'pageTitle=@bali',
    'created_date' =&gt; '2017-10-20 02:41:08',
    'updated_date' =&gt; '2017-10-20 02:41:08',
    'status' =&gt; 'active',
    'site' =&gt; 
    array (
      'id' =&gt; 1,
      'name' =&gt; 'Demo Site',
    ),
  ),
  2 =&gt; 
  array (
    'idcustomreport' =&gt; 5,
    'idsite' =&gt; 1,
    'revision' =&gt; 0,
    'report_type' =&gt; 'table',
    'name' =&gt; 'Country by New/returning with a filter',
    'description' =&gt; '',
    'category' =&gt; 
    array (
      'id' =&gt; 'CustomReports_CustomReports',
      'name' =&gt; 'Custom Reports',
      'order' =&gt; 65,
      'icon' =&gt; 'icon-business',
    ),
    'subcategory' =&gt; NULL,
    'dimensions' =&gt; 
    array (
      0 =&gt; 'UserCountry.Country',
      1 =&gt; 'CoreHome.VisitorReturning',
    ),
    'metrics' =&gt; 
    array (
      0 =&gt; 'nb_uniq_visitors',
      1 =&gt; 'goal_7_conversion',
      2 =&gt; 'goal_7_conversion_uniq_visitors_rate',
    ),
    'segment_filter' =&gt; 'countryCode!=pl',
    'created_date' =&gt; '2018-01-26 03:51:11',
    'updated_date' =&gt; '2018-01-26 03:51:11',
    'status' =&gt; 'active',
    'site' =&gt; 
    array (
      'id' =&gt; 1,
      'name' =&gt; 'Demo Site',
    ),
  ),
  3 =&gt; 
  array (
    'idcustomreport' =&gt; 8,
    'idsite' =&gt; 1,
    'revision' =&gt; 0,
    'report_type' =&gt; 'evolution',
    'name' =&gt; 'Evolution KPIs',
    'description' =&gt; '',
    'category' =&gt; 
    array (
      'id' =&gt; 'CustomReports_CustomReports',
      'name' =&gt; 'Custom Reports',
      'order' =&gt; 65,
      'icon' =&gt; 'icon-business',
    ),
    'subcategory' =&gt; NULL,
    'dimensions' =&gt; 
    array (
    ),
    'metrics' =&gt; 
    array (
      0 =&gt; 'nb_uniq_visitors',
      1 =&gt; 'goal_7_conversion',
      2 =&gt; 'goal_7_conversion_uniq_visitors_rate',
      3 =&gt; 'goal_4_conversion',
    ),
    'segment_filter' =&gt; '',
    'created_date' =&gt; '2018-04-03 02:55:32',
    'updated_date' =&gt; '2018-04-03 02:55:32',
    'status' =&gt; 'active',
    'site' =&gt; 
    array (
      'id' =&gt; 1,
      'name' =&gt; 'Demo Site',
    ),
  ),
);