Query root type must be provided error

I have a nodeJS Apollo server and the server is working fine when I run in development mode. But when I use webpack to build for production I get the following error.

Error: Query root type must be provided.
    at Un (C:\xxxxxx\dist\index.js:2:1612273)
    at Function.generateSchemaDerivedData (C:\xxxxxx\dist\index.js:2:1248625)
    at Object.schemaDerivedDataProvider (C:\xxxxxx\dist\index.js:2:1243311)
    at new t.SchemaManager (C:\xxxxxx\dist\index.js:2:1323703)
    at new N (C:\xxxxxx\dist\index.js:2:1243228)
    at Object.63607 (C:\xxxxxx\dist\index.js:2:1138699)
    at __webpack_require__ (C:\xxxxxx\dist\index.js:2:2367097)
    at C:\xxxxxx\dist\index.js:2:2368032
    at Object.<anonymous> (C:\xxxxxx\dist\index.js:2:2368060)
    at Module._compile (node:internal/modules/cjs/loader:1105:14)

I have a basic webpack setup:

const path = require('path');

module.exports = {
    entry: './src/index.ts',
    mode: 'development',
    module: {
      rules: [
          test: /\.tsx?$/,
          use: 'ts-loader',
          exclude: /node_modules/,
    resolve: {
      extensions: ['.tsx', '.ts', '.js', '.mjs'],
    output: {
      filename: 'index.js',
      path: path.resolve(__dirname, 'dist'),
    target: 'node',
    optimization: {
        usedExports: true,

Here is a screen shot of my schema.