The latest version of the AsyncCssPlugin is not compatible with 4.x releases of the HtmlWebpackPlugin.

Using a 4.x release (4.3 at the writing of this issue) will result in the following error:

AsyncCssPlugin[error]: htmlWebpackPluginAlterAssetTags is undefined. Is your configuration missing the HtmlWebpackPlugin?

This is because HtmlWebpackPlugin had a refactoring with version 4.0 and changed something with the hooks (see changelog).

Is it possible to make this plugin compatible with HtmlWebpackPlugin 4.x?