Hi @winpeace,

Thank you for the details. Somehow the custom pop-up form you use doesn't send $user_data variable. We just addapted wpForo core for such cases. You cam make that change on your copy of wpForo plugin and update it in future without any issue. Please open this file:

/wp-content/plugins/wpforo/wpf-includes/wpf-hooks.php

Find this line:

function wpforo_replace_retrieve_password_message( $message, $key, $user_login, $user_data ) {  

Change it to this:

function wpforo_replace_retrieve_password_message( $message, $key, $user_login = '', $user_data = array() ) {  

Thank you @Robert. Works !