I get the error message 'Invalid Product Key - Couldn't write to PREF-file' when Activating NTFS for Mac

Trying to activate NTFS for Mac results in an error message

Most commonly this error results from trying to install an old version of NTFS for Mac on an operating system it does not support. Please download the latest installer from here, and retry the installation.

If you still get the same error, please remove the settings file and try again.

How to remove the existing settings file

• Open Terminal (Applications → Utilities → Terminal)
• Issue the command:
  

  sudo rm -f "/Library/Preferences/com.tuxera.NTFS.plist"

If the problem persists, you can contact our support team at macsupport@tuxera.com