My course isn't working. Several Issues: 1. When I invite

My course isn't working. Several Issues:
1. When I invite a student to the course it takes them to the course page. Once student presses enroll button, the page blurs and student is unable to move forward.
2. When student visits page to manually enroll bypassing the invite, student presses enroll button and page blurs. If student presses button again through blurred page, page refreshes and works as usual.
3. Open-ended section of courses causes page to time out and never load. one example of page is attached.