The other day I was checking one of our courses to see if it was ready for Fall semester and I clicked on a page which returned this error “The page you requested does not exist. For your convenience, a search was performed using the query node OR 153” but didn’t know what was the problem. This problem came about from deleting the instructional designer who created the pages for this course from Drupal. to fix the problem I used Navicat Database Admin Tool and went into the course’s NODE table and changed the pwnership of the missing pages to 1 (system Admin) and cleared cache to make the pages appear again. Lesson learned is never delete any user but revoke their roles.