Hello William,
Thank you for your message.
Unfortunately, the "update is required" displaying in Viewer for Mac/Linux for Hosts running the latest 7.0.2.0 version is expected behavior as it is a newer version of Remote Utilities. In our future updates, we'll make the program update Hosts' version information immediately during the online status check without the user having to log in on the Hosts at all. Sorry for the inconvenience.
In addition, please try logging in/connecting to a remote Host from your Viewer and see if this helps to update the version information.
Hope that helps.