You could just sketch the open profile, then do a contour flange, I'm sure that would work in v11.
Alternatively,
To fix your model (this worked for me in 2010) follow these steps
1. Delete the flat pattern
2. Move the "End of Folded" marker to just below "Fold 1"
3. Highlight the large flat surface
4. Click flat pattern (it should flatten)
5. Click back to the folded part
6. Move the "End of Folded" marker to just below "Fold 2"
7. Then click flat pattern again
That is what worked for me, I know they have overhauled the sheet metal module since v11 so it may not work for you.
Ryan
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