I know this is old but it could probably help someone who got stuck on this like me: 
	Since I have a fresh installation of both Cakewalk and Keyzone in my system, I had to go to Cakewalk > Edit > Preferences (shortcut P) > File > VST Settings > VST Scan Paths > Add > 'C\program Files\VST plugins'. 
	Make sure 'Automatic Background Scan' is selected under 'Scan Options' else you'd need to 'Scan' manually.
 
	(ref below screenshot) 
	(ref