Schools and universities across the country are recovering from an outage that knocked down Canvas , an online platform that manages exams, course notes, lecture videos and grades. The disruption tied to a cyberattack hit in the middle of finals period for many colleges, a high-stress time when students and instructors rely heavily on the platform. By late Thursday, Instructure, the parent company of Canvas, said the platform was available again to most users. The hacking group ShinyHunters