Could you please error message for coursepro plugin

Installed Coursepro and got this error message. I removed the plugin, but the error is still showing at the top of the page

this is the error message:

Warning: Creating default object from empty value in /home/content/p3pnexwpnas01_data03/25/2236225/html/wp-content/plugins/coursepress/includes/first-install.php on line 256