I am not exactly sure where the issue is and maybe
@colleague will spot something more likely.
The only thing I spotted that is different that what I saw in the video post by colleague is that your Background Layer is no longer labeled as such where as in the video it always Keeps that name. I do know that if you try and create a mask on the Background Layer it will comply yet then rename your Layer as Layer 0. From the Action steps it is still trying to reference the Layer "Background" yet it is not there.
As I said, I am not sure this is the issue yet if you created a Layer Mask on the Background Layer before running the Action, that could be your issue. There is no where in the video where I saw the Background Layer converted to having a mask. Or it could be a bug in the Action itself.
That is the first discrepancy that stood out to me.
As I said, that may not be the issue .
John Wheeler