Can't revolve from 3D Sketch

I have inserted a plane in a 3D sketch and offset it from aface.
After sketching the feature and centerline and exiting the sketchcommand I'm prompted that the selected centerline is invalid.
I've noticed that the direction arrow is parallel to the planeunlike when creating a revolved feature that was sketched directlyon a plane (the arrow points "normal to" the plane).
I'm new to SW and figure I must be going about this the wrong way.
SolidworksParts And Features