I have a sheet metal part, which I was able to flatten in the past. Now it won’t do it. See:

When the feature tree shows the flat pattern as suppressed

The part looks like this:

With the flattened pattern enabled

very little happens to the part:

If anything, it isn’t flattned. What could be the cause of this?

I am doing this in SolidWorks 2014 SP3.0.