Can't create a simple sweep

[dmbyrnes122575]

Please see the attached. I'm attempting to sweep some deck panels across a bridge structure. I've had no problem with 3 of the 4 segments by adding a model-in-place component, choosing structural foundations and supplying a name, then choosing Sweep, picking the edge of one of the girders for the path, and then choosing a profile family for the profile. The profile appears at the plane location in the correct position, but when I check to finish, I get "Error - cannot be ignored - Can't create sweep". Revit is giving no hint why it can't create the sweep, and I don't see how the girders between these two pier caps are different from the others.

Any ideas, anyone?

[Craig_L]

you've chosen a complicated way of placing these, try the beam system its faster, easier and less prone to errors, its also easy to add or remove members and alter the extents with the beam system function