I recently moved our ithinksharepoint.com domain on to Office 365.
Unfortunately once we switched over the default domain of ithinksharepoint.sharepoint.com to ithinksharepoint.com we could no longer access the SharePoint online teamsite or edit the public website page.
The error displayed was as follows:-
A support call with Microsoft was raised on the Office 365 site. After a few days Jon from the support team called and explained that Office 365 didn’t support custom domains which ended sharepoint.com.
This issue is due to be fixed but there is no current timeline for when.
I will be publishing a workaround to this issue in a future post.