Call2Teams - Customers
You are in the process of adding the Teams Service using the OneClick method and see the following Sync error:
What Does This Mean?
As per the Teams OneClick setup guide: Teams Service OneClick Setup you need to have a spare user licence available to allow Call2Teams to automatically configure your DNS entries. If this is not available the setup process cannot complete.
The simplest way to resolve this issue to to provide an unallocated user licence on the Microsoft 365 account and run Sync Now again.
For the domain activation you're going to need at least one (preferably two) unused licences of any the following types:
The spare licence can be removed after the setup and Sync successfully completes. This link will explain further and advise on ways to make a licence available: Microsoft Spare Licence Options
This is the longest part of the automated process since DNS records have to migrate through many systems within Microsoft. Keep returning to the Call2Teams page and refreshing to keep abreast of the status.