Course Press Pro does not allow me to create a new course

I have installed CoursePress Pro on my multisite, activated it, chosen the course press theme and begin to make a course.

When I get to the Description on the second step, it won't allow me to write anything in the box. Therefore I am unable to proceed.

A similar issue occurred when I set up a course on a separate WP site a month ago and would make an update, but Coursepress wouldn't save the changes... therefore I could not continue.

Have others complained of the issue? How can I fix it?