Error: Data structure returned is not convertible in the requested format. Try to call this method with the parameters '&format=original&serialize=1'; you will get the original php data structure serialized. The data structure looks like this: $data = array ( 0 => array ( 0 => array ( 0 => '2024-03-22', 1 => array ( 'count' => 0, 'starred' => 0, ), ), 1 => array ( 0 => '2024-03-23', 1 => array ( 'count' => 0, 'starred' => 0, ), ), 2 => array ( 0 => '2024-03-24', 1 => array ( 'count' => 0, 'starred' => 0, ), ), 3 => array ( 0 => '2024-03-25', 1 => array ( 'count' => 0, 'starred' => 0, ), ), 4 => array ( 0 => '2024-03-26', 1 => array ( 'count' => 0, 'starred' => 0, ), ), 5 => array ( 0 => '2024-03-27', 1 => array ( 'count' => 0, 'starred' => 0, ), ), 6 => array ( 0 => '2024-03-28', 1 => array ( 'count' => 0, 'starred' => 0, ), ), ), );