There's no problem about the way your trying to unfold. There is no solution to unfold the file. Somethimes Inventor likes to go one way, and somethimes like to go other way, maybe if you do the sketch in another plane, maybe itr
starts to works ( it's math!!! ).
The important thing is: its better to know several processes to achieve the same result, mainly in sheet metal... and in this case you had learned two different aproaches for the same part!!
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