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any buddy guide me about these error when am try to open the file Creo 3.0 shutdown?
Yes and no. Sheetmetal requires a constant thickness or it will fail unfold/flatten. It basically stops being sheetmetal once a feature is coined or otherwise formed to less than or greater than its given thickness.
You might be able to do this as a two stage part. I haven't tried it yet, but a basic sheetmetal part could be brought into an assembly and from there, do a secondary operation if you are removing material. You would have to try this as I haven't confirmed you can do this if the part is sheetmetal.
What you can do is make sheetmetal part with constant thickness, unbend, remove material then bend back.