Error: Data structure returned is not convertible in the requested format: Only integer keys supported for array columns on base level. Unsupported string 'metadata' found for row 'array (
  'metrics' => 
  array (
    'nb_visits_0' => 
    array (
      'name' => 'Germany (Visits)',
      'logo' => 'plugins/Morpheus/icons/dist/flags/de.png',
      'min' => 0.0,
      'max' => 52.0,
      'change' => '+0%',
    ),
    'nb_visits_1' => 
    array (
      'name' => 'China (Visits)',
      'logo' => 'plugins/Morpheus/icons/dist/flags/cn.png',
      'min' => 0.0,
      'max' => 25.0,
      'change' => '-100%',
    ),
    'nb_visits_2' => 
    array (
      'name' => 'Switzerla'. Try to call this method with the parameters '&format=original&serialize=1'; you will get the original php data structure serialized.