Well, i have the same problem here.
Analyzing the console, I realized that the problem was in the way jQuery is called. I went to check what changed with that in the update of WordPress to 5.3 and I saw the reference to this error “Uncaught TypeError: $ is not a function” in this post here: https://www.ads-software.com/support/topic/read-this-first-wordpress-5-3-master-list/#post-12124062
I searched about it and managed to solve (for now) my problem by changing the following file:
wp-content/plugins/coursepress/2.0/asset/js/coursepress-unitsbuilder.js
in the line 1459, i change $ for jQuery, getting like this:
this.jQuery(‘.unit-save-button’).removeClass( ‘disabled’ );
Remembering, back up the files you want to change. I’m still testing, but so far everything is ok.
