No valid license has been found on this computer

Hiii,
i had registered my license on my steinberg account on but in my steinberg account only cubase can be dowloaded from the downloads sections in my prodeucts. I had downloaded some of the VST instuments like The Grand 3, HALion 6 and Wavelab Pro 9.5 using the Steinberg Download Assistant but i am unabl to use them. Whenever i open any of these the message is prompted.
“NO VALID LICENSE HAS BEEN FOUND ON THIS COMPULTER”.
PLEASE HELP ME OUT