Minimum Age for WooCommerce v1.0.17 has been released. It fixes a bug in an email filter hook.
woocommerce_email_order_meta_fields filter hook allows developers to add data to WooCommerce order emails. A bug in Minimum Age for WooCommerce meant that when the date of birth was not added to order emails, it broke the filter hook for other plugins. Sorry about that! Now fixed.
You can update to the latest version from your WordPress plugin admin page. Here’s the full changelog for Minimum Age for WooCommerce.