I have the exact same issue, only I'm running it on a brand new Win 10 Pro edition PC. I am also a new patron for Presonus this month, and so far very excited and satisfied with the Studio software with the exception of the paid SonusSphere version of the Notation app software. Most instruments wont load because the VTS are not available to be managed/enabled etc. They were totally missing from the app install packet. PLEASE HELP ASAP! We are very much looking forward to using Presonus products exclusively in our production studio and the notation software must be of an exceptional quality and run smooth without hiccups and lags. So far very disappointed with Notation piece of things, I'm one of the composers in our group and it's impossible at this point to move forward without a fix on this. Thank you in advance.