I used the following Article to renew my unexpired Exchange Federation Certificate successfully.
https://docs.microsoft.com/en-us/exchange/renew-the-federation-certificate-exchange-2013-help
After that i left the Old one there. Now since the old one is expired, its showing in the ECP notification all the time.
I am unable to delete it from ECP, it error out.
Does anyone experience that, please share your process to remove the expired one.
ZakBhai