Check box not displaying

I’m trying to create an application form with a check box at the end. The text for the box displays, however the actual box to check doesn’t.

Please help, your form is the only one I want to use (its great).

I’m using the Thesis theme / framework.

Thank you!!!

Here is a link to the test page: https://stiblermortgages.com/mortgage-application

I am in the process of adding https to it, so if it doesn’t work…add the s.