I have a relatively simple V shaped sheetmetal part that I am detailing. I placed the flat pattern on the sheet and then created a couple of projected views. I then changed the projected views to be the default formed views. As the sheet also has a lip on the sheet I placed a section view on one of the legs placing the cut plane perpendicular to the leg. The view appears to be created and the view label is created but there is nothing in the view. I was able to create the desired view by creating a new parent view and sectioning that so I guess the problem has been solved, but, I was wondering if anyone knew why the original projected view would not provide the same results.
The issue is due to fact that parent view (not the project from which you're creating the section view) is a flat pattern view. So if you change that to same as parent view, the section works as needed. Check section view B-B
This is a known issue, so please vote for SPR #: 973155 and 680921 and use the workaround you're using.