I can not see the part but can see the feature in the tree. How can I get the part back?
RMB on the part in the feature tree and select either Isolate or Move with triad (if you need it moved).
Or Show (in case it is hidden) or Unsuppress (in case it is suppressed) or Zoom to Selection (in case it has just flown off screen).
But ultimately, can you post a screen shot of what the feature tree looks like? This will give us a clue as to what is going on.
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