thank you for the reply MIke. I have of course contacted Steinberg support. However I have seen - if I remember correctly - forum posts about steinberg changing its sales model. I was hoping that forumites might be able to point me to a way to reauthorise my exiisting Halion Sonic - or advise me that i would need a new subscription. Often advice in the forum is faster than support from suppliers.

as for 'yes -and' i noted the fact that the standalone version doesn't work either to help eliminate this as a PG Music/BIAB issue. It's a Steinberg problem. I actually downloaded the HAlion Sonic as part of the Dorico package following advice in the forum. While I wait for Steinberg any help from the forum from members who have had a similar problem and solved it would be gratefully received and a reply showing I am not alone would at least reassure me.