After a Time Machine file restore, you may encounter this activation error, even if the license is properly activated in the iLok License Manager software.
How to fix this:
You MUST first be logged in as user that has administrator access. (if you only have one user / login on your Mac, then that account will be your administrator).
Open a macOS terminal ( /Applications/Utilities/Terminal.app ) and copy this command into the command line and press Return:
You'll now be prompted to enter your macOS current user session.
Now your product should be properly activated.