Board Thread:Questions and Answers/@comment-30557719-20161121005806/@comment-33390855-20171017015237

I know this is almost a year late, but in case you were still wondering, yes it's common on Macs, especially in early versions of the game. I bought the game when it came out,  I had never attempted a Genocide Route, only a Neutral and then Pacifist, and still got the souless pacifist ending. I told several forums and no one knew or heard of this problem. The glitch seems to be that the system information file that triggers the ending is randomly downloaded when on a Mac. This video explains how to fix it (it's the same for Mac, too).