If you are getting a blank or invalid challenge code while using Mac, please follow these steps:
1) Using Finder, navigate to the following location -
Macintosh HD/ Library/ Preferences/SystemConfiguration
2) Delete the any of the following files you see there:
(***you may not have this one)
3) Restart your Mac
After restarting your Mac, please check to see if the challenge code has been generated by clicking on the "Request Authorization" button.
If you continue to run into issues, please contact us at firstname.lastname@example.org.