The requested domain name is not configured for any web site:
https://connect.mandela.ac.za:443/Blogs/Adventures-of-a-Blended-Learning-Techie/May-2012/Using-Facebook-in-the-classroom
If you're an administrator of this site, you need to go to
Site Manager -> Sites
and use the following domain name either in the Site properties or add a new domain alias:
connect.mandela.ac.za:443