Halion Sonic SE - Dorico can't find LA Studio, Reverence Reverb

I had a problem with the sound relating to open hi-hat. It wouldn’t play.
So I decided to do a fresh install.
First I uninstalled Halion Sonic SE and made sure to delete every folder/file that was halion related. Then restarted my computer and installed Halion Sonic SE again. Now Dorico can’t find LA Studio, Reverence Reverb, which it apparently is depended upon to play anything. And I can’t find it either.
Please help?