Why can't I intersect these 2 objects? I've created these 2 objects and want to create a new object that represents the area where they intersect. I'm really confused as to why I cannot do it. I practiced on a cube and a cylinder in a new file and it work as expected. How do I find the issue with these objects?


You can check out the file in question.
You have doubles , flipped normals and ngons in your meshes.   

Select the object named mask, enter edit mode and do the following :  

-select all vertices , press w and remove doubles.
-recalculate normals with ctrln  

result :