Pro X5 worked fine, but recent upgrade to Pro X6 does not. Opens with usual Monitor 1, all windows, but blank left Monitor 2. All is fine on Monitor 1. When I scrub or edit, Monitor 2 shows a small video copy of Program Window in a small screen, which also plays in the Program Monitor at top left of Monitor 1 (duplicate video playing). If I drag Program window from Monitor 1 to Monitor 2, it works fine. If I then go to full screen, it works fine. If I drag Program Window back to Monitor 1, instead of usual desktop back on Monitor 2, it shows a blank black screen. When I edit or play, what is in Program Window also plays on the blank screen of Monitor 2 but in a small window. No controls - it is not really the Program Window, but video shows like it. This did not happen with Pro X5 before "upgrade."
Using Win7, 8 core AMD cpu, 16 g RAM, SSD C drive, 5 additional internal drives.