Membership Registration Add field

Hi WPMU,

First of all great plugin. And great support site. I am bringing up a familiar question of how to add a field to the registration page. Unfortunately, Buddypress blows up my admin for some reason so it is out of the question.

I have updated my account page to include extra fields(I don't want users going to the WP profile) and everything works great.

I have updated my registration page to show the fields I want to add. However, I cannot seem to get the added fields to post on registration. They end up blank on the account page.

I have followed the method highlighted in this thread.
https://premium.wpmudev.org/forums/topic/membership-plugin-add-custom-fields-to-registration-form

I see many suggestions from Barry to take a look at invite.simplecodes.php, however, I am needing a bit more insight on how to code this(an example of adding first_name would be brilliant!). The solution provided above is a lot leaner, however it doesn't seem to work for me.

I realize this is a customization over support question.