Reports have been emerging that sessions using the new 64-bit AAX version of UVI Workstation are causing Mini Grand to lose sound. This is a confirmed bug.
No word on this bug from UVI yet; however, a workaround is to instantiate UVI Workstation LAST on a session - also, make the UVI plugin INACTIVE before saving the session, which will force other VIs to load before UVI when reopening that session. Once the session is open, go ahead and reactivate UVI.
We’ll let you know when there’s a permanent fix.