Hello, I'm having the same issue, but I'm unsure how to fix it, I know of the same bug, but anytime I had an update that messed it up, I would just delete everything, redownload ff vii through steam, convert it again, then redownload all the mods in 7th heaven and that worked for me each time.
But now that I had to force myself to upgrade to windows 10 before it didn't become free anymore way back, I haven't been able to play it in awhile. The deleting everything doesn't work anymore, so it can't be tied to my sound since, when converting the steam version each time I set my sound device. Yet it still does the same thing each time, I don't know what to do.