How do I update my Rosetta Stone Version 3.5.3 to comparability with todays Mac OS ?

RODietz wrote:

How do I update my Rosetta Stone Version 3.5.3 to comparability with todays Mac OS ?

With the release of macOS 10.15 Catalina and moving forward... applications will have to be 64-bit.

App developers will issue updated apps if they want their apps to work on this newest macOS upgrade(s)

32-bit app compatibility with macOS... - Apple Support

https://support.apple.com/en-us/HT208436

Check Your Apps and Prepare for a 64-bit World

https://www.stclairsoft.com/Go64/index.html

Locate all 32-bit apps in System Info

http://osxdaily.com/2018/03/06/find-32-bit-apps-mac/

Looking through their website, it doesn't appear they have any version that will run on a modern operating system. The online versions require Adobe Flash which Adobe has stopped supporting.

The CD versions require a macOS prior to Catalina.