If you have experienced trouble logging in to Shibboleth the following information may help:
To access Course Reserves, browsers must be set to accept third-party cookies from <northwestern.ares.atlas-sys.com>. Also, clearing your browser's cache may help.
To learn more about managing browser settings, please see the NUIT help page. [1]
Please call 1-Help for further help.
Links:
[1] http://www.it.northwestern.edu/security/browser-management/index.html