I have 2 old OSX who accept only V12.0.223866 and I try to etablish the connection and it says that the version is our-of-date. I can't reach the place ,where the MacBook, is locate by myself.
All the best
The free license users have not the feature to connect over older versions of the TeamViewer app, like the licensed users.
I would suggest you contact the support team for further information or to buy a license.