CodeIgniter Form validation fails and doesn't show a message - php

Question

I have a dynamic form that is generated depending on how many people are selected from another page. When I submit this form however, the form validation fails without giving me an error. Could someone take a look and see why it's failing? I have tried debugging it but I can't see it. Maybe my method is wrong? This form used to work as well. It started to not work after I added the form processing for the children. Hopefully someone can help. Thank you so much.
Controller
<?php
defined('BASEPATH') OR exit('No direct script access allowed');
class Details extends TX_Controller {
public function __construct(){
parent::__construct();
ini_set('memory_limit', '64M');
$this->load->model('TransactionsModel');
$this->load->model('ProductsModel');
}
public function index(){
$data['productdetail'] = $this->ProductsModel->getProduct($this->session->userdata('productid'));
// var_dump($data['productdetail']);
$data['adults'] = $this->session->userdata('adults');
$data['children'] = $this->session->userdata('children');
$this->load->view('public/publicMenu/navigationLink');
$this->load->view('public/publicDetails/details',$data);
$this->load->view('public/publicMenu/navigationJquery');
}
public function next(){
$adultlength = $this->input->post('adults');
$childrenlength = $this->input->post('children');
$this->form_validation->set_error_delimiters('<p class="error">', '</p>');
for ($i=0; $i < $adultlength; $i++) {
$this->form_validation->set_rules('inputfirstname['.$i.']', 'Firstname', 'trim|required');
$this->form_validation->set_rules('inputlastname['.$i.']', 'Lastname', 'trim|required');
$this->form_validation->set_rules('inputdateofbirth['.$i.']', 'Date of Birth', 'trim|required');
$this->form_validation->set_rules('inputicnumber['.$i.']', 'IC Number', 'trim|required');
$this->form_validation->set_rules('inputmobilenumber['.$i.']', 'Mobile Number', 'trim|required');
$this->form_validation->set_rules('inputemail['.$i.']', 'Email', 'trim|required');
$this->form_validation->set_rules('inputconfirmemail['.$i.']', 'Confirm Email', 'trim|required');
$inputfirstname[] = $this->input->post('inputfirstname['.$i.']');
$inputlastname[] = $this->input->post('inputlastname['.$i.']');
$inputdateofbirth[] = $this->input->post('inputdateofbirth['.$i.']');
$inputicnumber[] = $this->input->post('inputicnumber['.$i.']');
$inputmobilenumber[] = $this->input->post('inputmobilenumber['.$i.']');
$inputemail[] = $this->input->post('inputemail['.$i.']');
$inputpostcode[] = $this->input->post('inputpostcode['.$i.']');
}
for($j=0;$j<$childrenlength;$j++){
$inputchildfirstname[] = $this->input->post('inputchildfirstname['.$j.']');
$inputchildlastname[] = $this->input->post('inputchildlastname['.$j.']');
$inputchilddateofbirth[] = $this->input->post('inputchilddateofbirth['.$j.']');
}
if($this->form_validation->run()==false){
$data['productdetail'] = $this->ProductsModel->getProduct($this->session->userdata('productid'));
$data['adults'] = $this->session->userdata('adults');
$data['children'] = $this->session->userdata('children');
$this->load->view('public/publicMenu/navigationLink');
$this->load->view('public/publicDetails/details',$data);
$this->load->view('public/publicMenu/navigationJquery');
}else{
for ($i=0; $i < $adultlength; $i++) {
$passengerdetails[] = array(
'firstname'=>$inputfirstname[$i],
'lastname'=>$inputlastname[$i],
'dateofbirth'=>$inputdateofbirth[$i],
'icnumber'=>$inputicnumber[$i],
'mobilenumber'=>$inputmobilenumber[$i],
'email'=>$inputemail[$i],
'postcode'=>$inputpostcode[$i],
'usertype'=>'adult'
);
}
if($childrenlength>0){
for($j=0;$j<$childrenlength;$j++){
$childpassengerdetails[] = array(
'firstname'=>$inputchildfirstname[$j],
'lastname'=>$inputchildlastname[$j],
'dateofbirth'=>$inputchilddateofbirth[$j],
'icnumber'=>'',
'mobilenumber'=>'',
'email'=>'',
'postcode'=>'',
'usertype'=>'child'
);
}
$this->session->set_userdata('childpassengerdetails',json_encode($childpassengerdetails));
}
$this->session->set_userdata('passengerdetails',json_encode($passengerdetails));
redirect('/Public/Payment');
}
}
}
View
<section id="about" class="container content-section text-center">
<div class="row">
<div class="col-lg-8 col-lg-offset-2">
<h2><?php echo $productdetail->name;?></h2>
<h2>Enter Passenger Details</h2>
<?php echo form_open_multipart('Public/Details/next','class="inputform"');?>
<h3>Adults</h3>
<?php for($i=0;$i<$adults;$i++){?>
<input type="hidden" class="form-control" name="adult" value="<?php echo $adults;?>">
<label for="inputfirstname">Firstname</label>
<input type="text" class="form-control" name="inputfirstname[]" placeholder="Firstname" value="<?php echo set_value('inputfirstname['.$i.'],""');?>">
<div class="errormessage"><?php echo form_error('inputfirstname['.$i.']'); ?></div>
<label for="inputfirstname">Lastname</label>
<input type="text" class="form-control" name="inputlastname[]" placeholder="Lastname" value="<?php echo set_value('inputlastname[$i]');?>">
<div class="errormessage"><?php echo form_error('inputlastname['.$i.']'); ?></div>
<label for="inputdateofbirth">Date of Birth</label>
<input type="date" class="form-control" name="inputdateofbirth[]" value="<?php echo set_value('inputdateofbirth[$i]');?>">
<div class="errormessage"><?php echo form_error('inputdateofbirth['.$i.']'); ?></div>
<label for="inputicnumber">IC Number</label>
<input type="text" class="form-control" name="inputicnumber[]" placeholder="IC Number" value="<?php echo set_value('inputicnumber[$i]');?>">
<div class="errormessage"><?php echo form_error('inputicnumber['.$i.']'); ?></div>
<label for="inputmobilenumber">Mobile Number</label>
<input type="text" class="form-control" name="inputmobilenumber[]" placeholder="Mobile Number" value="<?php echo set_value('inputmobilenumber[$i]');?>">
<div class="errormessage"><?php echo form_error('inputmobilenumber['.$i.']'); ?></div>
<label for="inputemail">Email</label>
<input type="text" class="form-control" name="inputemail[]" placeholder="Email" value="<?php echo set_value('inputemail[$i]');?>">
<div class="errormessage"><?php echo form_error('inputemail['.$i.']'); ?></div>
<label for="inputconfirmemail">Confirm Email</label>
<input type="text" class="form-control" name="inputconfirmemail[]" placeholder="Confirm Email" value="<?php echo set_value('inputconfirmemail[$i]');?>">
<div class="errormessage"><?php echo form_error('inputconfirmemail['.$i.']'); ?></div>
<label for="inputaddress1">Address</label>
<input type="text" class="form-control" name="inputaddress1[]" placeholder="Address 1" value="<?php echo set_value('inputaddress1[$i]');?>">
<input type="text" class="form-control" name="inputaddress2[]" placeholder="Address 2" value="<?php echo set_value('inputaddress2[$i]');?>">
<input type="text" class="form-control" name="inputaddress3[]" placeholder="Address 3" value="<?php echo set_value('inputaddress3[$i]');?>">
<input type="text" class="form-control" name="inputaddress4[]" placeholder="Address 4" value="<?php echo set_value('inputaddress4[$i]');?>">
<input type="text" class="form-control" name="inputaddress5[]" placeholder="Address 5" value="<?php echo set_value('inputaddress5[$i]');?>">
<label for="inputpostcode">Postcode</label>
<input type="text" class="form-control" name="inputpostcode[]" placeholder="Postcode1" value="<?php echo set_value('inputpostcode[$i]');?>">
<div class="errormessage"><?php echo form_error('inputpostcode['.$i.']'); ?></div>
<?php } ?>
<?php if($children>0){ ?>
<h3>Children</h3>
<?php for($j=0;$j<$children;$j++){ ?>
<input type="hidden" class="form-control" name="children" value="<?php echo $children;?>">
<label for="inputchildfirstname">Firstname</label>
<input type="text" class="form-control" name="inputchildfirstname[]" value="<?php echo set_value('inputchildfirstname[$j]');?>" placeholder="Firstname">
<label for="inputchildlastname">Lastname</label>
<input type="text" class="form-control" name="inputchildlastname[]" value="<?php echo set_value('inputchildlastname[$j]');?>" placeholder="Lastname">
<label for="inputchilddateofbirth">Date of Birth</label>
<input type="date" class="form-control" name="inputchilddateofbirth[]" value="<?php echo set_value('inputchilddateofbirth[$j]');?>">
<?php }} ?>
<p><button type="submit" class="btn btn-primary">Next</button></p>
<p>Cancel</p>
<?php echo form_close(); ?>
<p><?php echo $this->session->flashdata('Form'); ?></p>
</div>
</div>
</section>