Corridor missing in Cross Section Views of Civil 3D - Solution

Causes:

• Your sample lines do not sample the corridor, this means the corridor is not defined to display in the section views
• Your section view elevation range is not matching the corridor elevation (especially true if your corridor profile is shorter than the corridor itself, the corridor will make the waterfall effect) so the corridor is display "ouside the section view
• Your sample lines do not cross the corridor (it may happen when the corridor you try to display in the section view is not from the same alignment as the sample lines

Solution:

• Sample the corridor:
  1. Select sample line and right-click on it
  2. Choose Sample Line properties and select it again
  3. In Sections tab make sure all surfaces and corridors are sampled

• Extend the corridor profile and/or double check the elevation of the profile view 

1. Right-click on Profile used in corridor
2. Go to Elevation tab of Corridor Properties
3. Review elevations

• Make sure the sample lines cross the corridor