Last thing I could think about is the way you've authorized KICK 2.
If you authorized online via "connect" to your account, use your S.A account Username, not your email.
If it's a recent purchase, make sure you've confirmed your email ( you would have received an email from S.A, check your spam folder as well ).
But that should be all done, otherwise you would have an error message when authorizing.
Alternatively you can try the Offline Authorization method.
Get back to the the Manual Uninstall if you're not sure about files left on your computer.
Edit : You should see a keyfile in this location if KICK 2 has been correctly authorized.
Deleting all files in this directory deactivate the plugin and reset all settings to default, that's an easy way to reset everything and go back to the activation screen next time your open Kick 2 in your DAW.
C;/Users/Your_Username/AppData/Roaming/Sonic Academy/Kick 2
AppData might be hidden by default, you'll need to reveal hidden files & folders in Windows Explorer.
If none of the above works, then shoot an email to firstname.lastname@example.org