More than one of our customer opened tickets reporting that Free/Busy lookup between Cloud users and OnPrem Users has stopped working.
After checking the standard settings like autodiscovery, ews services, etc. is seems that this issue was related to the delegation trust and the token validation, maybe due some Microsoft “operations” or issues on their federation services.
In order to test this:
[PS] C:\Windows\system32>Test-FederationTrust -UserIdentity firstname.lastname@example.org
Continue Reading →