Don’t know what caused it exactly, but I experienced similar problems the first time I tried it over a year ago. It would often freeze up on me or crash, and I ended up returning it mainly for that reason. I never had any problems with the newer Synchron player, so it seemed to be something isolated to the older Vienna Imperial software.
However, I decided to give it another shot this fall and downloaded the 30-day demo which worked perfectly this time, so I assume they issued a software update at some point in between that addressed whatever was causing the crashes.
You might want to try reinstalling just to see if that helps.