Microsoft has released security updates (SUs) that resolve vulnerabilities found in:
Exchange Server 2013
Exchange Server 2016
Exchange Server 2019
IMPORTANT: When manually installing SUs...
Updated Mar 16, 2022
Version 6.0
Blog Post
After installing the patch both OWA and EAC stopped loading. OWA.Proxy HealthSet was in an unhealthy state. When trying to invoke the probe, we got error 500 Internal error. We had event 1003 in the Application log. We also got the same error trying to login to OWA on the server itself.
Running (Get-AuthConfig).CurrentCertificateThumbprint | Get-ExchangeCertificate | Format-List resulted in certificate not found.
Following the steps here to generate a new cert https://docs.microsoft.com/en-us/exchange/troubleshoot/administration/cannot-access-owa-or-ecp-if-oauth-expired seems to have fixed the issue with OWA and EAC. We still need to run through full testing to be sure this is the only issue. This does not seem entirely related to the cert issue outlined in this article. Can you confirm that is directly related to that issue and not an entirely separate bug?