Digicert made a oopsie. They had an error in their Domain Name Validation for each and every cert they issued from June 8th and before.
So what do they do? They decided to invalidate all certs issued by them before June 8th.
They gave 15-hour notice to all companies worldwide that they would need to update their certs, or they would be invalidated and domains would go down. (July 30th, 3:00 pm EDT. Notice was given at 11:00 pm July 29th).
A couple of companies got together and filed a temporary restraining order against Digicert to stop the invalidating of certs. Through lawyers, Digicert now has a deadline for everyone to refresh certs by 3:00 pm EDT today (July 31st). Companies can file an extension until August 3rd.
To say it's been a cluster f is a gross understatement.