If you have a Corporate licence, I would recommend updating your TeamViewer client via the MSI package.
You can simply create a new GPO and deploy TeamViewer 12 in order to update all of your machines in one go.
If you do not have access to the MSI package, I am afraid you will have to update your TeamViewer clients manually . You can do this either by connecting to them and clicking on "Remote update" in the toolbar of your connection window or by selecting "Help > Check for new version" in the main window of the local TeamViewer client.
I hope this was helpful!
All the best,
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