You can config file by this command:

• grep -rl "Could not detect Mac OS X Version from sw_vers output:" /Applications/Appium.app/

• Terminal will show : /Applications/Appium.app//Contents/Resources/node_modules/appium/node_modules/appium-support/build/lib/system.js /Applications/Appium.app//Contents/Resources/node_modules/appium/node_modules/appium-support/lib/system.js /Applications/Appium.app//Contents/Resources/node_modules/appium-support/build/lib/system.js /Applications/Appium.app//Contents/Resources/node_modules/appium-support/lib/system.js

• Use command vim and config each file.

Example

vim /Applications/Appium.app//Contents/Resources/node_modules/appium/node_modules/appium-support/build/lib/system.js

Config file:

1. Change From ->

   case 10: _arr = ['10.8', '10.9', '10.10', '10.11']; _i = 0; 

   To ->

   case 10: _arr = ['10.8', '10.9', '10.10', '10.11','10.12']; _i = 0;

vim /Applications/Appium.app//Contents/Resources/node_modules/appium/node_modules/appium-support/lib/system.js

Config file:

1. Change From ->

   try { stdout = (await exec('sw_vers', ['-productVersion'])).stdout; }

   To ->

   try { stdout = (await exec('sw_vers', ['-productVersion'])).stdout.trim(); }

2. Change From ->

   for (let v of ['10.8', '10.9', '10.10', '10.11']) { if (stdout.indexOf(v) === 0) { return v; } } 

   To ->

   for (let v of ['10.8', '10.9', '10.10', '10.11','10.12']) { if (stdout.indexOf(v) === 0) { return v; } }

vim /Applications/Appium.app//Contents/Resources/node_modules/appium-support/build/lib/system.js

Config file:

1. Change From ->

   case 10: _arr = ['10.8', '10.9', '10.10', '10.11']; _i = 0;

   To ->

   case 10: _arr = ['10.8', '10.9', '10.10', '10.11','10.12']; _i = 0;

vim /Applications/Appium.app//Contents/Resources/node_modules/appium-support/lib/system.js

Config file:

1. Change From ->

   try { stdout = (await exec('sw_vers', ['-productVersion'])).stdout; }

   To ->

   try { stdout = (await exec('sw_vers', ['-productVersion'])).stdout.trim(); }

2. Change From ->

   for (let v of ['10.8', '10.9', '10.10', '10.11']) { if (stdout.indexOf(v) === 0) { return v; } }

   To ->

   for (let v of ['10.8', '10.9', '10.10', '10.11','10.12']) { if (stdout.indexOf(v) === 0) { return v; } }

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