When a federated user signs out of a Microsoft cloud service such as Office 365, Microsoft Intune, or Microsoft Azure, the user receives the following error message on login.microsoftonline.com:
There is a problem with this website's security certificate
This issue occurs when an HTTP URL is used for the logout URL, but the logout process uses HTTPS to access the URL. If the URL can't accept HTTPS connections, the user receives the error message.
For example, this issue occurs if the logout URL is http://idp.contoso.edu/idp/logout.htm and the logout process tries to access it by using https://idp.contoso.edu/idp/logout.htm.
To protect the confidentiality of personally identifiable information (PII) that's contained in the Security Assertions Markup Language (SAML) logout request, a secure (HTTPS) connection is required. Review your security token service (STS) documentation to determine what the logout URL should be.
To resolve this issue, try Method 1. If Method 1 doesn't resolve the issue, use Method 2.
Method 1: Make sure that the logout URL can accept HTTPS requests
Update the logout URL so that it can accept HTTPS requests. To do this, open the Azure Active Directory Module for Windows PowerShell, and then run the following cmdlet:
Microsoft Azure cloud services, Microsoft Azure Active Directory, Microsoft Office 365, Microsoft Intune, CRM Online via Office 365 E Plans, Microsoft Azure Recovery Services, Office 365 Identity Management