Adding a contact profile to a contribution page (user registration)
It sounds like the problem is the one described here: Backbone isn&#39;t loading on Civi 4.6.11/WP 4.4.1

Please try changing your theme to the default theme, which doesn't conflict with Backbone.  If you find that this solves the problem, you can follow the instructions on the other question on dequeuing Backbone from your WordPress theme.