VST not working (disabled)

Hi,
I have installed some (64 bit) VST’s in the right folder (c:\program fils\VstPlugins), and I see most of them in cubase, but many of them are like “disabled”, not colored (please see attached screenshot), so I can’t select them.

what should I do?

here is the screenshot:


more info:
Cubase 10.5 pro
windows 10 64 bit

thanks!