Hey there, Ys Fans. If you've been having some trouble starting The Oath in Felghana where your screen blacks out and you need to reboot, you're suffering from a very specific issue due to incompatibility with FFDSHOW's mpeg1 decoder speedup tricks.
The remedy for this is to go into your FFDSHOW video decoder settings and under Info and Debug and add YSF_Win.exe and YSF_Win_DX9.exe to the little box marked "don't use FFDSHOW in."
This bug has nothing to do with Nightwolve's patch and is a problem with either FFDSHOW or Falcom.
By the way, Thanks, Nightwolve, for helping me resolve this issue