Saving an Image after using a star selection layer

[Fay]

I have been processing using a star selection layer. Flattened the image & saved but it only saves as a black blank image. Please has anyone an idea of what I am doing wrong?

It looks normal in PS, although there is a histogram still there for the star layer. If I open image in Astroart, it is the feathered star layer that is on there, not the finished image. Hope someone can understand this.

Martin B may know the answer, as I followed his tutorial

Thanks a lot

Fay