If you have upgraded your Skype for Business users to Teams and want to update the Teams co-existence mode to “Teams Only” so that users can only use Teams but still join meetings hosted in Skype for Business.
To change the coexistence mode. Open Teams Admin Portal -> Org-wide settings -> Teams upgrade
Change the co-existence mode to “Teams only”. You may get below error as we see in the below screenshot. There is not much information on this portal to troubleshoot this issue. However, we will try using powershell to set the co-existence mode to “Teams only” mode to see if we get more information on the console.
Using Powershell command provides more information about the issue:
To check if any one is set to Skype for Business only, you should check using below command and make sure no one is set to Skype for Business only mode.
Get-CsOnlineUser | FT userprincipalname,TeamsUpgradeEffectiveMode
To Fix this issue, Create below two highlighted CNAME records in your Public DNS Management Console. Try again after few hours.
Now, we should be able to change the Coexistence mode to “Teams Only”.