"One of your on-premises Federation Service certificates is expiring" message in Office 365 portal

Problem

You receive the following message in the Microsoft Office 365 portal:

One of your on-premises Federation Service certificates is expiring. Failure to renew the certificate and update trust properties within 13 days will result in a loss of access to all Office 365 services for all users.

Cause

The Secure Sockets Layer (SSL) certificate or the token-signing certificate is about to expire. You may receive this message even if automatic certificate rollover is enabled for the token-signing certificate. 

Solution

To resolve this issue, follow these steps:

  1. Install the Microsoft Azure Active Directory Module for Windows PowerShell on the computer (if the module isn't already installed).
  2. Follow the steps in the "Scenario 1: The AD FS token-signing certificate expired" section in "There was a problem accessing the site" error from AD FS when a federated user signs in to Office 365, Azure, or Intune
  3. Follow the steps in How to update or repair the settings of a federated domain in Office 365, Azure, or Intune

More information

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