I'm working on a sheet metal part which I'm trying to flatten to create 2D drawings from. The error I seem to be having is edge-flange9 doesn't want to flatten. First, it shows one error of fixing one of the flange lines selected. If I remove that line from the flange parameters box, a different one under the same feature shows the error. Unfortunately this is the case with all of the flange parameters selected within that feature. Could anyone guide me as to why that is? I have attached my part for viewing.