To resolve this issue, use one of the following methods, as appropriate for your situation.
Method 1: Troubleshoot AD FS service availability issues
To investigate and resolve service availability issues with the AD FS service, see the following Microsoft Knowledge Base articles: �
2419389�Internet browser cannot display the AD FS webpage when a federated user tries to sign in to Office 365 web resources �
2712961�How to troubleshoot the AD FS connection
Method 2: Troubleshoot AD FS�communication SSL certificate problems
To investigate and resolve service SSL certificate issues with the AD FS service, see the following Microsoft Knowledge Base article: �
2523494�You receive a certificate warning from AD FS when you access Office 365 web resources by using a federated account �
Method 3: Reset the AD FS�service endpoints to the default configuration
To make sure that the AD FS service endpoints are set up to support SSO authentication, see the following Microsoft Knowledge Base article:
2712957�SSO authentication to Office 365 fails after you change AD FS service endpoint settings in the AD FS Management Console�
As soon as the AD FS service endpoints are updated, it's important to also sync the AD FS service metadata to Windows Azure Active Directory (Windows Azure AD). To do this, use the "How to update the configuration of the Office 365 federated domain" section of the following Microsoft Knowledge Base article: �
2647048 How to update or to repair the configuration of the Office 365 federated domain