CoursePress Plugin Not Working

When I installed CoursePress using your wordpress dashboard the plugin caused many of my sites files to have errors and I had to go into the cPanel to delete the plugin and re-upload all of the affected files.

It created fatal errors with WP-settings.php and wp-includes/capabilities.php and also wp-includes/widgets/class-wp-widget-pages.php

Now I cannot use my site at all without fixing code. Please help me fix this. Now I will be extra wiery of installing any of your plugins of which I am paying quite a bit of money monthly for.