Peter
I have the same problem as Hector on this.
On the left side of the 3-D layer configuator is a slice list for slice with buttons for "status" ("fixed", etc.) and "button" ("view...") for each slice. When I click on "view", a new dialog opens. This dialog has a plan view of the slice and two windows, one to the left and one to the bottom, for displaying the slice configuration cross-section for the position of the cross hairs in the plan view. I do not see the cross-section profiles. Each profile window has a slider bar, but sliding it does not reveal a profile line.
Since first using FEFLOW v.4.8, I have never seen this feature to work.