I have a extrusion that will not convert to sheetmetal. I get the pop up "cannot be a bend edge as there is a face for the edge which is non planar". I do not understand why it must be planar if i am converting a bend?

I have tried a couple of ways to make this into sheetmetal with no luck. I have tried breaking it up into pieces. Any advise or direction in how to overcome it would be greatly appreciated.

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