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 (
  'date' =&gt; 'Mon, Mar 27',
  'previousPages' =&gt; 
  Piwik\DataTable::__set_state(array(
     'rows' =&gt; 
    array (
      0 =&gt; 
      Piwik\DataTable\Row::__set_state(array(
         'label' =&gt; 'divezone.net/diving/bonaire',
         'referrals' =&gt; 1,
      )),
    ),
     'currentId' =&gt; 1,
     'depthLevel' =&gt; 0,
     'indexNotUpToDate' =&gt; true,
     'rebuildIndexContinuously' =&gt; false,
     'tableSortedBy' =&gt; false,
     'queuedFilters' =&gt; 
    array (
    ),
     'disabledFilters' =&gt; 
    array (
    ),
     'rowsCountBeforeLimitFilter' =&gt; 0,
     'enableRecursiveSort' =&gt; false,
     'enableRecursiveFilters' =&gt; false,
     'rowsIndexByLabel' =&gt; 
    array (
    ),
     'summaryRow' =&gt; NULL,
     'totalsRow' =&gt; NULL,
     'metadata' =&gt; 
    array (
    ),
     'maximumAllowedRows' =&gt; 0,
  )),
  'previousSiteSearches' =&gt; 
  Piwik\DataTable::__set_state(array(
     'rows' =&gt; 
    array (
    ),
     'currentId' =&gt; 2,
     'depthLevel' =&gt; 0,
     'indexNotUpToDate' =&gt; true,
     'rebuildIndexContinuously' =&gt; false,
     'tableSortedBy' =&gt; false,
     'queuedFilters' =&gt; 
    array (
    ),
     'disabledFilters' =&gt; 
    array (
    ),
     'rowsCountBeforeLimitFilter' =&gt; 0,
     'enableRecursiveSort' =&gt; false,
     'enableRecursiveFilters' =&gt; false,
     'rowsIndexByLabel' =&gt; 
    array (
    ),
     'summaryRow' =&gt; NULL,
     'totalsRow' =&gt; NULL,
     'metadata' =&gt; 
    array (
    ),
     'maximumAllowedRows' =&gt; 0,
  )),
  'pageMetrics' =&gt; 
  array (
    'loops' =&gt; 1,
    'pageviews' =&gt; 25,
    'entries' =&gt; 23,
    'exits' =&gt; 16,
  ),
  'followingPages' =&gt; 
  Piwik\DataTable::__set_state(array(
     'rows' =&gt; 
    array (
      0 =&gt; 
      Piwik\DataTable\Row::__set_state(array(
         'label' =&gt; 'divezone.net/jobs',
         'referrals' =&gt; 2,
      )),
      1 =&gt; 
      Piwik\DataTable\Row::__set_state(array(
         'label' =&gt; 'divezone.net/diving/dominican-republic',
         'referrals' =&gt; 1,
      )),
      2 =&gt; 
      Piwik\DataTable\Row::__set_state(array(
         'label' =&gt; 'divezone.net/diving/solomon-islands',
         'referrals' =&gt; 1,
      )),
      3 =&gt; 
      Piwik\DataTable\Row::__set_state(array(
         'label' =&gt; 'divezone.net/jobs/apply/divemaster-2',
         'referrals' =&gt; 1,
      )),
      4 =&gt; 
      Piwik\DataTable\Row::__set_state(array(
         'label' =&gt; 'divezone.net/jobs/preview',
         'referrals' =&gt; 1,
      )),
      5 =&gt; 
      Piwik\DataTable\Row::__set_state(array(
         'label' =&gt; 'Others',
         'referrals' =&gt; 2,
      )),
    ),
     'currentId' =&gt; 3,
     'depthLevel' =&gt; 0,
     'indexNotUpToDate' =&gt; true,
     'rebuildIndexContinuously' =&gt; false,
     'tableSortedBy' =&gt; false,
     'queuedFilters' =&gt; 
    array (
    ),
     'disabledFilters' =&gt; 
    array (
    ),
     'rowsCountBeforeLimitFilter' =&gt; 0,
     'enableRecursiveSort' =&gt; false,
     'enableRecursiveFilters' =&gt; false,
     'rowsIndexByLabel' =&gt; 
    array (
    ),
     'summaryRow' =&gt; NULL,
     'totalsRow' =&gt; NULL,
     'metadata' =&gt; 
    array (
    ),
     'maximumAllowedRows' =&gt; 0,
  )),
  'followingSiteSearches' =&gt; 
  Piwik\DataTable::__set_state(array(
     'rows' =&gt; 
    array (
    ),
     'currentId' =&gt; 4,
     'depthLevel' =&gt; 0,
     'indexNotUpToDate' =&gt; true,
     'rebuildIndexContinuously' =&gt; false,
     'tableSortedBy' =&gt; false,
     'queuedFilters' =&gt; 
    array (
    ),
     'disabledFilters' =&gt; 
    array (
    ),
     'rowsCountBeforeLimitFilter' =&gt; 0,
     'enableRecursiveSort' =&gt; false,
     'enableRecursiveFilters' =&gt; false,
     'rowsIndexByLabel' =&gt; 
    array (
    ),
     'summaryRow' =&gt; NULL,
     'totalsRow' =&gt; NULL,
     'metadata' =&gt; 
    array (
    ),
     'maximumAllowedRows' =&gt; 0,
  )),
  'outlinks' =&gt; 
  Piwik\DataTable::__set_state(array(
     'rows' =&gt; 
    array (
    ),
     'currentId' =&gt; 5,
     'depthLevel' =&gt; 0,
     'indexNotUpToDate' =&gt; true,
     'rebuildIndexContinuously' =&gt; false,
     'tableSortedBy' =&gt; false,
     'queuedFilters' =&gt; 
    array (
    ),
     'disabledFilters' =&gt; 
    array (
    ),
     'rowsCountBeforeLimitFilter' =&gt; 0,
     'enableRecursiveSort' =&gt; false,
     'enableRecursiveFilters' =&gt; false,
     'rowsIndexByLabel' =&gt; 
    array (
    ),
     'summaryRow' =&gt; NULL,
     'totalsRow' =&gt; NULL,
     'metadata' =&gt; 
    array (
    ),
     'maximumAllowedRows' =&gt; 0,
  )),
  'downloads' =&gt; 
  Piwik\DataTable::__set_state(array(
     'rows' =&gt; 
    array (
    ),
     'currentId' =&gt; 6,
     'depthLevel' =&gt; 0,
     'indexNotUpToDate' =&gt; true,
     'rebuildIndexContinuously' =&gt; false,
     'tableSortedBy' =&gt; false,
     'queuedFilters' =&gt; 
    array (
    ),
     'disabledFilters' =&gt; 
    array (
    ),
     'rowsCountBeforeLimitFilter' =&gt; 0,
     'enableRecursiveSort' =&gt; false,
     'enableRecursiveFilters' =&gt; false,
     'rowsIndexByLabel' =&gt; 
    array (
    ),
     'summaryRow' =&gt; NULL,
     'totalsRow' =&gt; NULL,
     'metadata' =&gt; 
    array (
    ),
     'maximumAllowedRows' =&gt; 0,
  )),
  'referrers' =&gt; 
  array (
    0 =&gt; 
    array (
      'label' =&gt; 'Direct entries',
      'shortName' =&gt; 'direct',
      'visits' =&gt; 6,
      'details' =&gt; 
      array (
      ),
    ),
    1 =&gt; 
    array (
      'label' =&gt; 'From search engines',
      'shortName' =&gt; 'search',
      'visits' =&gt; 8,
      'details' =&gt; 
      array (
        0 =&gt; 
        array (
          'label' =&gt; 'Unknown',
          'referrals' =&gt; '6',
        ),
        1 =&gt; 
        array (
          'label' =&gt; 'diving protection',
          'referrals' =&gt; '1',
        ),
        2 =&gt; 
        array (
          'label' =&gt; 'divezone .net',
          'referrals' =&gt; '1',
        ),
      ),
    ),
    2 =&gt; 
    array (
      'label' =&gt; 'From websites',
      'shortName' =&gt; 'website',
      'visits' =&gt; 3,
      'details' =&gt; 
      array (
        0 =&gt; 
        array (
          'label' =&gt; 'http://scubadiverlife.com/gear/gear-review-cressi-medas-lady',
          'referrals' =&gt; '1',
        ),
        1 =&gt; 
        array (
          'label' =&gt; 'http://diveadvisor.com/united-kingdom/dive-shops',
          'referrals' =&gt; '1',
        ),
      ),
    ),
    3 =&gt; 
    array (
      'label' =&gt; 'From social networks',
      'shortName' =&gt; 'social',
      'visits' =&gt; 6,
      'details' =&gt; 
      array (
        0 =&gt; 
        array (
          'label' =&gt; 'reddit',
          'referrals' =&gt; '4',
        ),
        1 =&gt; 
        array (
          'label' =&gt; 'Facebook',
          'referrals' =&gt; '1',
        ),
        2 =&gt; 
        array (
          'label' =&gt; 'Instagram',
          'referrals' =&gt; '1',
        ),
      ),
    ),
  ),
);