My Stencil painting is not working, why?

I have checked everything I can think of, and it just won’t use the Stencil image.
It’s using the brush to paint directly.

Could someone have a look at my .blend file please?
TexturePaintingNOTworking.blend (1.2 MB)

Thanks a bunch guys!

Update - I was able to stencil-paint again once I appended the object to another file. So, I guess the original file got corrupt at some point (?).
Unfortunately it happened again in the new file too.