Muhammad,,, I think you were on the right track. I deleted your Sheet Metal feature and unsupressed your Thicken3. Then did an "insert bends" (not "Convert to Sheet Metal") and things worked out. Sometimes the Insert Bends is preferable.
Esternal Stringer_db.zip 229.9 KB
thank you so much Sir,
ah ok now understand i can pick also the edge.
i was continue try to picking the face...
now it's fine thanks.