Opencart payment gateway integration error for Paymark

Question

I bought this extension of - paymark from opencart market & uploaded it. When i am trying to install it / edit it , its giving me ERROR :

Notice: Undefined index: token in /home/pqdzt0xjgliy/public_html/products.thevirtualhands.org/admin/controller/extension/payment/paymark.php on line 67Notice: Undefined index: token in /home/pqdzt0xjgliy/public_html/products.thevirtualhands.org/admin/controller/extension/payment/paymark.php on line 72Notice: Undefined index: token in /home/pqdzt0xjgliy/public_html/products.thevirtualhands.org/admin/controller/extension/payment/paymark.php on line 77Notice: Undefined index: token in /home/pqdzt0xjgliy/public_html/products.thevirtualhands.org/admin/controller/extension/payment/paymark.php on line 80Notice: Undefined index: token in /home/pqdzt0xjgliy/public_html/products.thevirtualhands.org/admin/controller/extension/payment/paymark.php on line 82

I debugged it & found that, its giving this error, on all SSL lines. For e.g

$data['breadcrumbs'][] = array(
        'text' => $this->language->get('text_home'),
        'href' => $this->url->link('common/dashboard', 'token=' . $this->session->data['token'], 'SSL')
    );

$data['breadcrumbs'][] = array(
        'text' => $this->language->get('text_payment'),
        'href' => $this->url->link('extension/extension', 'token=' . $this->session->data['token'], 'SSL')
    );

SSL is enabled alraedy & working fine. Any idea, how to fix this ? n why this happening ?