CiviCRM profile/User Referral incompatibility

CiviCRM provides an option under 'CiviCRM > Administer CiviCRM > Custom Profiles > Settings' to include your own fields in the 'user registration' page. Using this breaks the User Referral registration process. After using the referral link, upon submission, the user IS created but the user ends up at blank page (user/registration). Reloading the page works OK. The user can then login, but the CiviCRM profile fields are not written to the database, and the referral table entry is not made.

I doubt there is an easy fix for this, but I wanted to post the conflict to save other CiviCRM users the time of figuring out the problem.

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