Clipping Mask not Working

[EngineerStoryteller]

In the past all I had to do to clip a picture a clipping mask was drag it underneath. Now, when I try, it doesn't work. The mask is a png. I've attached a screenshot. The very large picture is dragged under a mask. You can see that in the right hand column. But the picture is not clipping to the mask. I've included a screenshot of the mask as well. The weird thing is that this has worked on other templates that I used. Just not on this particular mask.

[firstdefence]

Make the mask a child of the image and change it's blend mode to screen, the blend mode: screen makes darker tones see-through and lighter tones opaque, so with regard to this mask the grey will be translucent and the black will be transparent.

I have removed the grey area for you and left the black. I would simply right click on the mask with transparency and select Mask to below.