无法在节点操作服务器中使用xml文件浏览所有节点

Question

在我的节点操作服务器中，我正在加载一个带有定义的节点和引用的XML文件。当我运行节点操作服务器并连接到它（使用统一的OPC客户端）时，我只能看到顶级节点。但是当我在客户端中浏览节点时，看到以下错误：

const server_options = {
//certificateFile: server_certificate_file,
//privateKeyFile: server_certificate_privatekey_file,
port: port,
nodeset_filename: [
path.join(rootFolder,"modeling/DDHubOPCUA.NodeSet2.xml"),
standard_nodeset_file
]
};
const server = new OPCUAServer(server_options);
const endpointUrl = server.endpoints[0].endpointDescriptions()  
[0].endpointUrl;

const hostname = require("os").hostname();
console.log("  server PID          :".yellow, process.pid);

server.on("post_initialize", function () {
const addressSpace = server.engine.addressSpace;
const rootFolder = addressSpace.findNode("RootFolder");
});
server.start(function (err) {
if (err) {
console.log(" Server failed to start ... exiting");
process.exit(-3);
}
console.log("  server on port      :".yellow, 
server.endpoints[0].port.toString().cyan);
console.log("  endpointUrl         :".yellow, endpointUrl.cyan);
console.log("\n  server now waiting for connections. CTRL+C to 
stop".yellow);
});