Frequent popups on clients with TeamViewerHost: License code not valid in TeamViewer.ini

Several of our Macintosh Catalina clients running the 'TeamViewer Host.app' have started getting frequent popup messages saying: " The license code in the 'TeamViewer.ini' configuration file is not a valid Enterprise Concurrent license. TeamViewer Portable is only running in limited demonstration mode. "   Please help us stop these messages.