Gulp didn't report an error after it started, but it can't be opened in the browser all the time. - Codes Helper

npm start run result

$ npm start

> voteapp@1.0.0 start E:\project\PumpkinCage\Pumpkin\server
> set NODE_ENV=development&& gulp default

[15:53:55] Using gulpfile E:\project\PumpkinCage\Pumpkin\server\gulpfile.js
[15:53:55] Starting "default"...
[15:53:55] Starting "build"...
[15:53:55] Starting "clean"...
[15:53:55] Finished "clean" after 30 ms
[15:53:55] Starting "fonts"...
[15:53:55] Starting "copy"...
[15:53:55] Starting "less"...
[15:53:55] Starting "js"...
[15:53:55] Starting "img"...
[15:53:55] gulp-fontmin: Minified 1 font
[15:53:55] Finished "less" after 409 ms
[15:53:55] Finished "copy" after 411 ms
[15:53:55] Finished "img" after 414 ms
[15:53:55] Finished "fonts" after 429 ms
[15:53:55] Finished "js" after 422 ms
[15:53:55] Starting "html"...
[15:53:55] Finished "html" after 47 ms
[15:53:55] Finished "build" after 512 ms
[15:53:55] Starting "nodemon"...
[15:53:55] [nodemon] 1.11.0
[15:53:55] [nodemon] to restart at any time, enter `rs`
[15:53:55] [nodemon] watching: *.*
[15:53:55] [nodemon] starting `node app`
[15:53:55] Finished "nodemon" after 98 ms
[15:53:55] Starting "browser-sync"...
[15:53:56] Finished "browser-sync" after 26 ms
[15:53:56] Starting "watch"...
:3000
:development
[BS] Proxying: http://localhost:3000
[BS] Access URLs:
 --------------------------------------
       Local: http://localhost:7000
    External: http://192.168.1.176:7000
 --------------------------------------
          UI: http://localhost:3001
 UI External: http://192.168.1.176:3001
 --------------------------------------
[BS] Watching files...

package.json partial code

"scripts": {
    "start": "set NODE_ENV=development&& gulp default",
    "pro": "set NODE_ENV=production& npm run build& node app",
    "restart": "forever restart bin/www",
    "stop": "forever stop bin/www",
    "build": "gulp build",
    "test": "node bin/www"
}

gulpfile.js file

"use strict";
var path = require("path");
var del = require("del");
var browserSync = require("browser-sync");
var runSequence = require("run-sequence");
var gulp = require("gulp");
var gulpif = require("gulp-if");
var minify = require("gulp-clean-css");
var nodemon = require("gulp-nodemon");
var cache = require("gulp-cache");
var uglify = require("gulp-uglify");
var htmlmin = require("gulp-htmlmin");
var fontmin = require("gulp-fontmin");
var less = require("gulp-less");
var concat = require("gulp-concat");
var jshint = require("gulp-jshint");
var cssBase64 = require("gulp-base64");
var autoprefixer = require("gulp-autoprefixer");
var rev = require("gulp-rev-ayou");
var revCollector = require("gulp-rev-collector-ayou");

var reload = browserSync.reload;

var NODE_ENV = process.env.NODE_ENV;

var staticPath = "dist/static/";

// 
// var zh_CN = require("./lang/zh_CN");
// var text = (function() {
//   var _text = "";
//   function TraversalObject(obj) {
//     for (var a in obj) {
//       if (typeof (obj[a]) == "object") {
//         TraversalObject(obj[a]); //
//       }
//       else {
//         _text += obj[a];
//       }
//     }
//   }
//   TraversalObject(zh_CN);
//   return _text + "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890.,;:\"(!?)+-*/=";
// })()

var text = "fdg"

// 
gulp.task("clean", function(cb) {
  return del(["dist/static/", "dist/views/"]);
});

// lib
gulp.task("copy", function(cb) {
  return gulp.src("./public/lib/**/*")
    .pipe(gulp.dest(staticPath + "lib"))
});

// fonts
gulp.task("fonts", function() {
  return gulp.src("./public/fonts/**/*")
    .pipe(fontmin({
      text: text
    }))
    .pipe(gulp.dest(staticPath + "fonts"))
});

// html
gulp.task("html", function() {
  return gulp.src(["dist/rev/**/*.json", "views/**/*.html"])
    .pipe(revCollector())
    .pipe(htmlmin({collapseWhitespace: true, minifyCSS: true, minifyJS: true}))
    .pipe(gulp.dest("dist/views/"))
});

// less
gulp.task("less", function () {
  return gulp.src("public/less/**/*.less")
    .pipe(less({
        paths: [ path.join(__dirname, "less", "includes") ]
    }))
    .pipe(cssBase64())
    .pipe(autoprefixer({
      browsers: ["last 2 versions", "Android >= 4.0", "last 3 Safari versions"],
      cascade: true, // :true :
      //-webkit-transform: rotate(45deg);
      //        transform: rotate(45deg);
      remove:true // :true
    }))
    .pipe(minify())
    .pipe(rev())
    .pipe(gulp.dest(staticPath + "css"))
    .pipe(rev.manifest())
    .pipe(gulp.dest("dist/rev/css"))
});

// js
gulp.task("js", function () {
    return gulp.src("public/js/**/*.js")
      // .pipe(jshint({

      // }))
      // .pipe(jshint.reporter("default"))
      .pipe(gulpif(
        NODE_ENV === "production" || NODE_ENV === "test",
        uglify({ compress: true }))
      )
      .pipe(rev())
      .pipe(gulp.dest(staticPath + "js"))
      .pipe(rev.manifest())
      .pipe(gulp.dest("dist/rev/js"))
});

// img
gulp.task("img", function() {
  return gulp.src(["public/img/**/*","public/img/*"])        //Img
    .pipe(gulp.dest(staticPath +  "img"));
});

// 7000Express3000
gulp.task("browser-sync", function() {
  var files = ["views/**/*.*","css/*.*","css/**/*.*","js/*.*","img/*.*"].map((a) => {
    return staticPath + a;
  })
  browserSync.init(null, {
    proxy: "http://localhost:3000",
    files: files,
    port: 7000
  });
});

// Express
gulp.task("nodemon", function (cb) {

  var started = false;

  return nodemon({
    script: "app"
  }).on("start", function () {
    // to avoid nodemon being started multiple times
    // thanks @matthisk
    if (!started) {
      cb();
      started = true;
    }
  });
});

gulp.task("build", function (cb) {
    runSequence("clean", ["fonts", "copy", "less", "js", "img"], "html", cb);
});

gulp.task("less-watch", ["less"], reload);
gulp.task("js-watch", ["js"], reload);
gulp.task("img-watch", ["img"], reload);
gulp.task("html-watch", ["html"], reload);

gulp.task("watch", function (cb) {
  // css
  gulp.watch("public/less/**/*.less", ["less-watch"]);

  // .js
  gulp.watch("public/js/**/*.js", ["js-watch"]);

  // lib
  // gulp.watch("public/lib/jquery-plugins/*.js", ["copy-watch"]);

  // 
  gulp.watch("public/img/**/*", ["img-watch"]);

  // ejs
  gulp.watch("views/**/*.html", ["html-watch"]);
});

gulp.task("default", function(cb) {
  runSequence("build", "nodemon", ["browser-sync", "watch"]);
});

app.js

var express = require("express");
var path = require("path");
var favicon = require("serve-favicon");
var cookieParser = require("cookie-parser");
var bodyParser = require("body-parser");
var swig = require("swig");
var env = require("./env").env;
var log4js = require("log4js");
var utils = require("./utils/utils");

var port = env.port;
var app = express();

var NODE_ENV = process.env.NODE_ENV || "development";

global.token = null;

// view engine setup
// Disables caching in Swig.
swig.setDefaults({ cache: false });
app.engine("html", swig.renderFile);
app.set("views", path.join(__dirname, "dist/views"));
app.set("view engine", "html");

// uncomment after placing your favicon in /public
app.use(favicon(path.join(__dirname, "favicon.ico")));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
let _maxAge = NODE_ENV === "production" ? 30*24*3600*1000 : -1;
app.use(express.static(path.join(__dirname, "dist/static"), {maxAge: _maxAge}));

// 
var appLog = log4js.getLogger("app"), // 
  httpLog = log4js.getLogger("http"); // 
global.appLog = appLog; // 
utils.mkdirsSync("../logs/node");
utils.mkdirsSync("../logs/c2node");
utils.mkdirsSync("../logs/node2s");
log4js.configure("./log4js.json");
app.use(log4js.connectLogger(httpLog, { level: "auto" }));

utils.autoLogin()
// 
require("./routes/index")(app);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error("Not Found");
  err.status = 404;
  next(err);
});

// error handlers

// 404
app.use(function(req, res, next) {
  var err = new Error("Not Found");
  err.status = 404;
  next(err);
});

// api
app.use("/api", function (err, req, res, next) {
  global.appLog.error("Api error :" + err && err.stack || err);
  res.json(err);
});

// 
app.listen(port, err => {
  console.log(err || ":" + port);
  console.log(":" + NODE_ENV);
});

browser: Port 3000 is the same