The client's Win7 PC is just a week old, but has been online without an anti-virus program, and has had no Win7 Updates installed yet.
The new Dell PC was delivered with Win7 installed, and came with the Win10 upgrade DVD. Upgrading the OS is likely, but will not be addressed until January.
TeamViewer Support indicated that the Adobe Flash Player error has been reported, and is currently being worked on, but I was able to find a single reference to the problem I encountered online (Google Search).
Is there anyone here that has encountered this error?