Problem
You’ve recently noticed that you receive the following message when logging into the Office 365 portal at https://portal.office.com:
One of your on-premises Federation Service certificates is expiring. Failure to renew the certificate and update trust properties within 27 days will result in a loss of access to all Office 365 services for all users.
You’ve checked your on-prem hosted ADFS server’s certificate and verified that it has not expired:
Solution
The following are 2 options I found after browsing the internet looking for an answer:
Option #1 – Manually renew the certificate
“One of your on-premises Federation Service certificates is expiring” message in the Office 365 portal
https://support.microsoft.com/en-ca/kb/2992335
Option #2 – Wait and allow certificate to auto renew
The following forum topic was responded by a Microsoft support representative indicating that the certificate should auto renew:
https://community.office365.com/en-us/f/613/t/173158
The day that I checked on the certificate was April 20 and launching the AD FS Management console on the ADFS server…
… then navigating to AD FS > Service > Certificates showed that the certificate was expiring on June 1 which was more than 20 days before the expiration date:
What I ended up doing was set up a calendar reminder on the 19 day before June 1 to check back and when I did on May 13, I noticed that the ADFS server had indeed renewed the Token-decrypting and Token-signing certificate the day before on May 12:
Logging onto Office 365 via https://portal.office.com also confirmed that the warning message was no longer displayed:
