So with css-loader version 3+, the option localIdentName is no longer supported, and the modules option has become an object that can contain the localIdentName option.

This causes addLessLoader to error if using this version of css-loader because the old localIdentName option is still being given:

    {
      test: lessModuleRegex,
      use: getLessLoader({
        importLoaders: 2,
        modules: true,
        localIdentName: localIdentName
      })
    }

You can see the change described above here:
https://github.com/webpack-contrib/css-loader/blob/master/CHANGELOG.md#breaking-changes