WooCommerce 3.0 makes some changes to its API that affect users who use WP-Members for additional WC registration fields.
WP-Members adds fields to the native WordPress registration using the WP action hook `register_form`. This action hook was also part of the WooCommerce registration form. In previous versions WC used its own hook, `woocommerce_register_form`, followed by WP’s register_form hook.
In WooCommerce 3.0, WP’s `register_form` action hook is no longer part of the WC registration form.
While I will be making some updates to WP-Members to account for this, I do not want to rush that process. Rather, I need to review some other changes in WC and make some updates that are more specific to WC rather than generic to WordPress.
In the meantime, if you have already updated to WooCommerce 3.0, note that the location of this change is one of WC’s template files. So it is OK for you to modify this file directly, provided that you are maintaining it in your theme folder and not the plugin folder. (Templates can be overridden by copying them to yourtheme/woocommerce/myaccount/.)
The template you can change is form-login.php. In the registration form section, at line 107, you’ll see the woocommerce_register_form action hook:
<?php do_action( 'woocommerce_register_form' ); ?>
Immediately after that, add this:
<?php do_action( 'register_form' ); ?>