"Halion One could not be found for VST synth..."

Halion One could not be found for VST synth…”

This is the message I get when I open Cubase 5 (32bit) on my W7 64bit OS. All my other plugins work fine but I can’t get Halion One (3) to install correctly or become visible. Thankfully I am running dual-boot (XP) until I can work out all the bugs. This is the only thing holding me up. Please help me. Thanks in advance.

PS. I’m using 5.5.3 (need to change that in my signature!)

Is it blacklisted?