I found this message when I made an edit to existing Quiz. I jst edit 'time limit'. After hit 'Save button, it said:
Fatal error: Call to undefined method wpdb::delete() in /home/sbymedia/public_html/smkpgri/wp-content/plugins/wp-pro-quiz/lib/model/WpProQuiz_Model_PrerequisiteMapper.php on line 4
Before change, 'Prerequisites' is currently inactive. I tried to activate 'Prerequisites', but error is still there.
How to solve this?