So I've always had mating issues (no pun intended), but most particularly with over-defining assemblies. For instance: I'm working on something now where there is an angle bracket which has a sensor mounted to the side of it by coincident in the X direction. Keep in mind, both of these are floating in space at this point. I then mate them in the Y direction, but theyr'e only mated together (they can still move in all directions in space). Now when I try to mate this angle to a plate in the Y direction, it says I'm over-defining the assembly. How can this be possible when they're obviously free-floating because they're able to move in all directions in space.

This is a very annoying and recurring issue I have and perhaps it's not simply user error?

Thanks.