Sudden disappearance of ntrack

N track 9. Windows 10. I was using n track (paid-for) on my desktop computer, when it just closed itself. Since then, even after a reboot, the n track button in the start menu tells me that the shortcut is no longer valid, and when I search the folder where it should be, everything else seems to be there except for ntrack.exe. Maybe my music’s bad, but is it really bad enough for n-track to commit suicide?
UPDATE; I’ve re-downloaded and re-installed, and it’s behaving itself so far.