While trying to connect to McGill’s wifi recently on my Chromebook I ran into an “Authentication Certificate Rejected Locally” error. Given that there is zero support for Chromebooks on the McGill IT pages, it took me a while to figure it out.
You just need to make sure that the server CA certificates are not being checked for. So instead of ‘Default’, select “Do Not Check” on the Server CA Certificate option on the Settings of the wifi connection. This should also work if you have the same problem on any other enteprise wifi connection.