Hi @Aschwanden Roger, ACA-IT-OPE-CIN ,
What's the version of the on-premises Exchange server?
I noted that you wasn’t able to run the HCW and did some steps manually. What are the steps? Has the hybrid environment been successfully deployed?
1.Have you read this article (Troubleshoot free/busy issues in Exchange hybrid environment )before? If not, please try the troubleshooting methods provided in the article first.
2.About the “Attempting to ping RPC proxy”. According to my test on the test account, the result shows that it is successful. If possible, please share the complete error message with us. But pay attention to covering your personal information. You also could hold the “Ctrl” and right click the outlook icon, then select the “Tesst E-mail AutoConfiguration” to test the Autodisocver service.
3.About the “ https status 504 (Gateway Timeout)”, It fails at EWS request and usually network related issues. Please run the following command to make sure that set the correct external URL and WSSecurity enabled as an authentication method.
Get-WebServicesVirtualDirectory | fl name,server,externalURL,ExternalAuthenticationMethods
4.According to my research, the Test-OrganizationRelationship cmdlet doesn't include any functional tests of federated sharing features, such as accessing user free/busy information or moving mailboxes between organizations. So please run the following command to check whether the settings of IOC and organizationrelationship are correct:
Get-IntraOrganizationConnector | fl TargetAddressDomains,DiscoveryEndpoint,Enabled
Get-OrganizationRelationship "Exchange Online to on premises Organization Relationship" | fl DomainNames,FreeBusy*,Target*,Enabled
For the usual settings, you can check at the bottom of this article: Demystifying Hybrid Free/Busy: what are the moving parts?
5.Status 401 indicates that access is denied. Regarding the 401-related error in IIS, you can refer to: HOWTO: Diagnose 401.x HTTP errors on IIS
6.Please run the following command to verify that that the OAuth configuration is correct.
Test-OAuthConnectivity -Service EWS -TargetUri <external hostname authority of your Exchange On-Premises deployment>/metadata/json/1 -Mailbox <Exchange Online Mailbox> -Verbose | Format-List
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