CoursePress logo will not change

The course press logo will not change. CoursePress Customizer doesn't work properly at all and it doesn't allow to change site logo. Upon using customize in the dashboard to set the logo of the course press theme it stays as the course press logo even after refreshing and emptying cache, all other graphics and links etc. update just fine.
Also when I enable the affiliate plugin, it gives an error - 500 and when I enable the enewsletter plugin, I can't use the customizer.