This error can occur due to limitations in your school’s network, especially if it is SSL or port 443.
Please contact the person/team responsible for managing your school’s network and inform them that our applications require access to the domain “classplash.com” and its subdomains (*.classplash.com) via port 443, which is used for secure https connections. Most importantly, the applications require access to the sub-domain “api.classplash.com”, which is used for license verification.