Applies to: Scarlett plug-in suite, Midnight plug-in suite
The Activate Button launches your Default Web Browser, so if this button isn't working it means you do not have a Default Web Browser set in your OS.
Here are instructions for setting a Default Web Browser in Windows and Mac. After setting this up the Activate Button will launch your browser and take you to the page to the Activation Page.
Windows: http://windows.microsoft.com/en-us/internet-explorer/make-ie-default-browser#ie=ie-11
Mac: https://support.apple.com/en-us/HT201607
If you have any further trouble please Contact Support.