Please click the link below to download TeamViewer 12 from the TeamViewer website - once installed please give the ID / Password to Technical Support.
TeamViewer Quick Support
https://get.teamviewer.com/y3kuk
Team Viewer for Windows
https://download.teamviewer.com/full
Team Viewer for MAC
http://download.teamviewer.com/download/version_12x/TeamViewerQS.dmg