Forum Discussion
Calendar button missing - On Prem 2016 Exchange
I had exactly the same issue as you and have solved it by following OAUTH manual setup to the letter via this doc https://docs.microsoft.com/en-us/exchange/configure-oauth-authentication-between-exchange-and-exchange-online-organizations-exchange-2013-help?redirectedfrom=MSDN
Get-IntraOrganizationConnector |fl Name,TargetAddressDomains,DiscoveryEndpoint,Enabled
brought no errors but no data. I had previously ran HCW and this completed with no errors (I assumed the hybrid process was fully complete). Exchange 2016 on premises, premium office 365 with licenses applied for exchange online plan. No mailboxes have been migrated, all are on premises. On premises existing Mail contacts and groups WERE visible in exchange online admin. AD Azure connect was already run with optional hybrid exchange enabled. Calendar button did not appear in teams. Teams worked otherwise.
So I ran the manual configuration of OAUTH from that link and calendar button started to appear after 30 mins. Again, these are ALL on premises mailboxes, we have not migrated any mailboxes yet.
One caveat, at the end of the process you need to create an AD object - this object had already been created so it looked like HCW had at least tried to make the OAUTH link but hadnt fully completed it.
HardWorkingITguy when you say you need to create an AD object, which one do you mean? The IntraOrganizationConnector? If yes, I see hybrid created one. Did you keep this one? or did you create the new one? or are you talking about something else?
PhillipPino You can look here https://techcommunity.microsoft.com/t5/exchange-team-blog/configuring-teams-calendar-access-for-exchange-on-premises/bc-p/1488629#M28422
You need OAUTH working between your tenant and on-prem. My colleagues successfully configured everything according article on how to configure OAUTH (you can find that link in a blog - it explains all the steps to configure OATH). But syncing accounts to the cloud makes better experience as you can select address from address book (also, easier to test). Product Group recommends to configure everything with HCW (it make things easier). Although you don't need transport to work between EXO and on-prem to make your calendar working. Anyway, if something doesnt work after HCW, you will go to that article about OATH to check spns in Azure AD and so on.