Tried to test it by going to an older save, but it still white screens. I also tried taking the CG movies from my old file and replacing the new file ones, however no dice unfortunately.
My current solution to fixing it is getting a cheat thing and changing the sapphire event completed variable to 2, so it just doesn't skips that CG and doesn't soft lock my game, which seems to work so far as the next 2 Sapphire events worked fine. Honestly can't think of another solution. Also thought a screenshot might help