No audio from projects after migrating to new iMac

So I’ve just used Migration Assistant to transfer from MacBook Pro to a new iMac using Catalina 10.15.6.
I can start a new project from scratch and record and playback fine (using UR22 and Cubase 10.5 and 10).
However when I load old projects most produce no audio on play back.
The projects load in properly with all plugins and play with track meters working correctly except for the master bus.
Audio connections etc are fine. I’ve tried using the internal speakers as well.

To make things more confusing I managed to get a very old project working.

Are there preferences operating here that might be stuffing things up (I had to delete 2 prefs relating to the UR22 before that interface would work)?

I doubt this is an isolated problem. Can somebody please help?


There are some permissions needed to be given to cubase on new installation.

Problem was plugins needing to be authorised. All going great now.