php获取component_verify_ticket？

public function index()

{    

    $timeStamp    ="";
    $nonce        ="";
    $encrypt_type ='';
    $msg_sign     ='';
    $encryptMsg   =file_get_contents('php://input');
    
    $result = $this->getVerify_Ticket($timeStamp,$nonce,$encrypt_type,$msg_sign,$encryptMsg);

    if($result){
        echo "success";
    }

}

//获取component_verify_ticket

public function getVerify_Ticket($timeStamp,$nonce,$encrypt_type,$msg_sign,$encryptMsg){

    $pc = new WXBizMsgCrypt(WxPayConfig::Token, WxPayConfig::EncodingAesKey, WxPayConfig::open_AppID);

    $xml_tree = new \DOMDocument();
    $xml_tree->loadXML($encryptMsg);
    $array_e = $xml_tree->getElementsByTagName('Encrypt');
    $encrypt = $array_e->item(0)->nodeValue;

    $format = "<xml><ToUserName><![CDATA[toUser]]></ToUserName><Encrypt><![CDATA[%s]]></Encrypt></xml>";

    $from_xml = sprintf($format, $encrypt);

    $msg = '';

    $errCode = $pc->decryptMsg($msg_sign, $timeStamp, $nonce, $from_xml, $msg);

    if ($errCode == 0) {

        $xml = new \DOMDocument();
        $xml->loadXML($msg);
        $array_e = $xml->getElementsByTagName('ComponentVerifyTicket');

        $component_verify_ticket = $array_e->item(0)->nodeValue;
        DB::getDB()->delete("wechat_verifyticket",'uptime!=1');
        DB::getDB()->insert("wechat_verifyticket",array(
            'component_verify_ticket'    => $component_verify_ticket,
            'uptime'                    => time()));

        return true;
    }else{
        DB::getDB()->delete("wechat_verifyticket",'uptime!=1');
        DB::getDB()->insert("wechat_verifyticket",array(
            'component_verify_ticket'    => $errCode,
            'uptime'                    => time()));
        return false;
    }

} 

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出错提示是什么？