Rufous

          Unable to load preload script even I followed the manual:https://nklayman.github.io/vue-cli-plugin-electron-builder/guide/guide.html#preload-files ,
I also tried many way I searched from github issuess  to resovle the problem . none of them works and I don't have any other way now . I think it maybe a bug but not pretty sure
I upload all the code to repo for the convenience of regenerate the problem.
https://github.com/codeh2o/electronVuePreloadIssue
Here is some snapshot:

// vue.config.js
module.exports = {
  transpileDependencies: ['vuetify'],
  pluginOptions: {
    electronBuilder: {
      nodeIntegration: true,
      builderOptions: {
        // Add also your database location
        extraResources: ['src', 'src/res/'],
        preload: 'src/preload.js',
      },
      // This line: add knex and sqlite3
      externals: ['knex', 'sqlite3'],
    },
  },
};

//background.js
async function createWindow() {
  // Create the browser window.
  const win = new BrowserWindow({
    width: 800,
    height: 600,
    webPreferences: {
      preload: path.join(__dirname,'preload.js'),
      // Use pluginOptions.nodeIntegration, leave this alone
      // See nklayman.github.io/vue-cli-plugin-electron-builder/guide/security.html#node-integration for more info
      nodeIntegration: process.env.ELECTRON_NODE_INTEGRATION,
      contextIsolation: !process.env.ELECTRON_NODE_INTEGRATION
    },
  });
  win.maximize();
  if (process.env.WEBPACK_DEV_SERVER_URL) {
    // Load the url of the dev server if in development mode
    await win.loadURL(process.env.WEBPACK_DEV_SERVER_URL);
    if (!process.env.IS_TEST) win.webContents.openDevTools();
  } else {
    createProtocol('app');
    // Load the index.html when not in development
    win.loadURL('app://./index.html');
  }
}