I was putting components into an assembly and was mating two faces that are parallel but when I try to mate them coincidentally or parallel, an error comes up that says:

"The components cannot be moved to a position which satisfies this mate. Planar faces are not Parallel. Angle is 0deg."

There is a picture attached...

This is not the first time this has happened, usually I just re-insert the component and it can solve the mate but thats not working this time.  What could cause this?