Win7, nVidia GForce 1060
Broken: 2.79.1 - 66c1b213 (2.78.c is broken also)
Short description of error
In the attached Blend file we have an object named Cover from which we try to extract via Difference Boolean Modifier two objects named Cutout and Cutout 2. With BMesh the thing doesn't work (press Apply - to see faces and vertices artifacts). Choosing Carve as Boolean library it works ok.