error in Session Codeigniter

Question

I have a dynamic menu that does a search in the bank and fills this menu, when I’m at home it works normally but when I change the page the value returns null and generates error in count(), I realized that every time I change page to table ci_session update at the bank, never touched the codeIgniter before and I don’t know if this is normal. Someone can help me?

$redes = $this->session->userdata('redes');
                            if(!empty($redes)) {
                                if (count($redes) > 0) {
                                    for ($i = 0; $i < count($redes); $i++) {
                                        echo '<li class="skew-25"><a href="' . $redes[$i]['url'] . '" target="_blank" data-title="' . $redes[$i]['titulo'] . '" data-tooltip="true"><span class="fa ' . $redes[$i]['class'] . ' skew25"></span></a></li>';
                                    }
                                }
                            }