I suspect that the sketch is open somewhere. (but don't know where)

I've been stuck on this for quite some time, any help would be greatly appreciated!

I suspect that the sketch is open somewhere. (but don't know where)

I've been stuck on this for quite some time, any help would be greatly appreciated!

Although Tom Gagnon's correct that there is a line over a line in the 3d sketch. Christie Wong, Are you actually trying to cut extrude the 3d sketch?

I did not examine your complete process because it uses some features which I don't. However, I think that this location may be ripe for investigation, as I found: