FLStudio's plugin manager is not up to date with the latest versions of the SDK.
This was taken from the page "VST 3 Locations / Format" in the SDK documentation:
[quote]
On the Windows platform a VST 3 Plug ...
resynthesizer vst plugin for a producer friend of mine who also uses flstudio to mix tracks
is there any way for him allow me access to it on my computer so I can use it with my flstudio account ? ...
FlStudio. I quickly closed the program to refreshed my Laptop and launched Studio back again, and as soon as I did it, the first problem came to me. A little window that said 'Fruity Limiter Plugin could not be found ...