OpenCart 3.0.2 Blank contact success page fix!

in catalog/controller/information/contact.php file

find:

$this->response->redirect($this->url->link('information/contact/success'));

add above:

$this->session->data['success'] = true;

Then, find:

$data['continue'] = $this->url->link('common/home');

add below:

if (!empty($this->session->data['success'])) {
			$data['text_success'] = $this->language->get('text_success');
			
			unset ($this->session->data['success']);
		}

In catalog/view/theme/<your_theme>/template/common/success.twig file

find:

</ul>

add below:

{% if text_success %}
  <div class="alert alert-success alert-dismissible"><i class="fa fa-check-circle"></i> {{ text_success }}</div>
  {% endif %}

This should resolved the problem.