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Rigs33's avatar
Rigs33
Copper Contributor
Apr 07, 2020
Solved

Teams Calendar Button missing - exchange 2010 + Exchange 2016 hybrid on-prem

Hello Tech community,   As you can see in the object, I have one Exchange 2010 sp3 RU22 and one Exchange 2016 CU12  (same forest). The 2016 is my hybrid server, all mailboxes are hosted on Exchang...
microsoft teams
  • Rigs33's avatar
    Rigs33
    Jul 14, 2020

    Hello fishizza,

     

    I had a long troubleshoot session with a Microsoft Exchange Escalation Engineer, it appears that the Teams Rest/API protocol  is not compatible with mailboxes created in Exchange prior to 2016 CU3.
    Finally, we migrated mailboxes directly to Office 365.

     

     

Rigs33's avatar
Rigs33
Copper Contributor
Apr 28, 2020
CAS and mbx still resides on EX2010, the case has been escalated to Microsoft on-prem experts.
I'm waitng for their feedback.
FYI, if i create a mbx directly on 2016 db, the calendar button appears in teams.
If I move a mbx from 2010 db to 2016 db, the calendar button is missing.
fatshark_2k's avatar
fatshark_2k
Brass Contributor
Apr 29, 2020
@riggs33 i just tested today myself. Mbx on 2016 has the calendar app in teams. Mbx on 2010 does not have a calendar app in teams. So mailbox should be on ex16 as requirement.
  • Rigs33's avatar
    Rigs33
    Copper Contributor
    Apr 29, 2020

    fatshark_2k As I mentioned in a previous post, according to this https://docs.microsoft.com/en-us/microsoftteams/exchange-teams-interact,  the requirement are:

    - sync running

    - Oauth configured properly

    - At least, Exchange 2016 cu3

    But nothing states clearly that the mailboxes have to reside on Exchange 2016 in a multi exchange environnement.

    And again, if I move a mailbox from 2010 db to 2016 db, the issue persist..... Whereas if I create a mailbox directly on 2016 db, we have the expected behaviour with Teams calendar.

     

    On your side, did you try to move a mailbox from ex2010 to ex2016, and see if the calendar  is showing up in Teams ?

    • fishizza's avatar
      fishizza
      Copper Contributor
      Jul 14, 2020

      Rigs33 

       

      Did you ever find a solution here?  I have a very similar problem with an onpremise Exchange 2013 and 2019 with hybrid setup between Online and 2019 box.  Moving users from onprem 2013 to 2019 is not getting me the calendars button in Teams for those users

      • Rigs33's avatar
        Rigs33
        Copper Contributor
        Jul 14, 2020

        Hello fishizza,

         

        I had a long troubleshoot session with a Microsoft Exchange Escalation Engineer, it appears that the Teams Rest/API protocol  is not compatible with mailboxes created in Exchange prior to 2016 CU3.
        Finally, we migrated mailboxes directly to Office 365.

         

         

    • fatshark_2k's avatar
      fatshark_2k
      Brass Contributor
      Apr 30, 2020

      Rigs33 , I tested with following. I have Exchange 2010 and Exchange 2016 in 1 organization. CAS namespace points to Exhange 2016 (autodiscover/webmail). Hybrid and Oauth configured on Exchange 2016. When a mailbox is on Exchange 2010 then the user has no calendar app/button in Teams. When i move the same mailbox to Exchange 2016 the user has the calendar app/button in Teams.

      Also stated in your article in the matrix is states 'User's mailbox is hosted in' and then for on-prem the requirement is Exchange 2016 Cu3+ so the mailbox has to be hosted in Exchange 2016 cu3+ 

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