The Courses Add-on in the WishList Member Add-ons plugin has 4 options to set as System Pages (Non-Members Page, Wrong Membership Level Page, etc).
If the Default option is selected for a System Page in the Courses Add-on, it will use what is set in the Advanced Options > Global Defaults > Error Pages section of WishList Member.
But there is an option to set individual Non-Members Pages, Wrong Membership Level Pages, etc. for each Course.
As an example, the Non-Members Page will appear to all non-logged in users/members (anyone not logged into the site) while the Wrong Membership Level Page will appear to logged in members who have a level(s) assigned to them, but don’t have the level with access to the course they tried to access.
The option to set the individual pages for each course is located in the Courses > Course Builder > *Click Course Title* > Access > System Pages section of WishList Member Add-ons.
This allows for specific information to be added to each page which can be used to show those users how to access/sign up for courses they currently cannot access.