Please note that the correct URL to access myCourses should be https://mycourses2.mcgill.ca. This URL brings you to McGill's ADFS sign-in page, similar to the Office 365 sign-in page.
Note that some older web pages were pointing to a different login page, where Shibboleth authentication was used. The old URL will be decommissioned as of May 4, 2020 and will no longer work. Website managers and editors should make sure to update their website links.