Hi All, Thanks for the answers -
I've since discovered on start up that Studio one is treating Melodyne as Blacklisted hence its not loading it, but no matter what I do. I cannot stop it being blacklisted. All plug ins are in the correct location etc. Strangely Melodyne now integrates with Ara using Logic Pro, and that works fine so it's not a melodyne install issue. So at least for now I have a workaround to move tracks to Logic for Melodyne edits.