UV Project Modifier in Cycles has no effect. What am I doing wrong? I put a UV Project Modifier on a Suzanne. I added an image plane with the texture I want to project onto Suzanne and positioned it.



Note: The texture is not showing as transparent in the screen shot because I forgot to check the settings for that in the menu when I used the Add Images as Planes add-on, but trust me that the texture does have alpha data.

I UV unwrapped Suzanne. The Image plane is already UV unwrapped because the add-on takes care of that. In the modifier's settings I specified the image plane as the projector object. I specified the UV map to be the only one that exists on my Suzanne ("UV Map"). I did not specify an image because I understand this is for Blender Internal only (correct me if I am mistaken - also I tried this once just in case but it made no difference). 



I created a Cycles material for Suzanne that uses the image from the image plane, and specified the coordinates to be from Suzanne's the UV map (which I expected to be modified by the modifier). The alpha from the image is supposed to factor between a plain Diffuse Shader and a textured one. However, nothing is showing up at all and although I read the Blender manual page on the UV Project Modifier I did not glean any answers from it. Can somebody please tell me what I've missed?
You need to select the image to use in the UV project modifier and enable Override image.
Your Diffuse nodes need to be flipped: