Hi Erodd
To add the read only class material back you >select add cloud storage
>select use a SharePoint Link
>add the library link.( you will get this from your sharepoint under classmaterials. Eg. Xxxxx.sharepoint.com/sites/xxxx/Class%20Materials
The xxxxx will be replaced by the link you have on your sharepoint.
>after you entered the library link click on go and the next.
Hope this helps you solve the issue.
Thanks
Dean Naidoo