"The HTTP request is unauthorized" error in a SharePoint Online calendar after you configure a calendar overlay to Exchange Online
Consider the following scenario:
- You have a calendar overlay in Microsoft SharePoint Online.
- You configure the calendar overlay to do the following:
- Retrieve a calendar from Microsoft Exchange Online
- Display the calendar within the SharePoint Online calendar
The HTTP request is unauthorized with client authentication scheme 'Ntlm'. The authentication header received from the server was 'Basic Realm=""'.
This issue occurs because the ability to use the calendar overlay in a SharePoint Online calendar that is retrieved from Exchange Online isn't supported.
Still need help? Go to the Office 365 Community website.
Article ID: 2997170 - Last Review: 03/16/2016 02:20:00 - Revision: 4.0
Microsoft SharePoint Online, Microsoft Exchange Online
- o365 o365e o365p o365a o365m o365022013 KB2997170