Hi Lisa,
The issue you are experiencing might be caused by client side. Please try the following steps to fix it:
1. Try to open the link with Internet Explorer 9.
2. Change another computer or network environment.
3. Please ensure to open the link in the same session as your Office 365 account. That means, before you open the link, please first login Office 365 with your administrator account.
In addition, I suggest you try to access the Admin page of your Office 365 portal to check it and see if it works properly now.
Thanks,
Reken Liu