The federation trust has changed to use a new certificate for Federation. You should update all TXT proof-of-ownership records ...

The federation trust has changed to use a new certificate for Federation. You should update all TXT proof-of-ownership records that were previously set in DNS for all the domains configured for Federation. The new hash-value should be replaced with the OrgNextCertificate proof value output of the OrgNextCertificate generated with "Get-FederatedDomainProof -DomainName example.com".