Error: Could not detect Mac OS X Version from sw_vers output

I am running the latest appium 1.7.1 with iOS.

When I run the appium-doctor I have notice to the below error:
ANy idea what does it it / effecting & how to overcome it?

Last login: Wed Sep 27 11:39:39 on ttys001
Menys-MacBook-Pro:~ menypeled$ ‘/Applications/Appium 2.app/Contents/Resources/node/bin/node’ ‘/Applications/Appium 2.app/Contents/Resources/node_modules/appium-doctor/appium-doctor.js’
info AppiumDoctor ### Diagnostic starting ###
info AppiumDoctor :heavy_check_mark: Xcode is installed at: /Applications/Xcode.app/Contents/Developer
[Error: Could not detect Mac OS X Version from sw_vers output: '10.12.6
']
Menys-MacBook-Pro:~ menypeled$