Close out of Imatest
Update the [imatest] section of your INI file to include the entry license_debug = 1.
license_debug = 1
If needed, here are instructions to help with this: How To: Find Your Default INI File.
Delete the .lic file from:
Mac: /Library/Application Support/Imatest
Restart your computer
Re-try the activation
If this does not work, please send us any log files located at C:\ProgramData\Imatest\license and C:\Users\<user>\AppData\Roaming\Imatest, and we will look into this further.
**NOTE: ProgramData and AppData are hidden folders. Instructions on how to view hidden files on Windows can be found here: https://support.microsoft.com/en-us/windows/view-hidden-files-and-folders-in-windows-97fbc472-c603-9d90-91d0-1166d1d9f4b5.