If you have not yet reviewed the Read Me files, I suggest that would be a good place to start. For answers and assistance with specific problems please provide a bit more information, such as a description of what you have done, results of those steps, and most importantly information about your computer OS (Windows/Mac version).
Mac OS 10.12, 10.14, 10.15, Win7, Win10
VDL2.5.5, Finale 2010-14.5, Finale 25-27
Kontakt 4-6, various other soft synths