From FreeCAD Documentation
- The workbench is affected by the topological naming issue that is inherent to FreeCAD. If an edit of a bend earlier in the history of the part renumbers the faces, then the following bends may be affected and switch faces. If the bend features do not break, you can double-click on it to get a dialog where you can select the proper face in the 3D view, and update the Bend.
- The Unfold tool has some limitations, and will fail in certain complex situations. When it fails, try to select a different face.
- Frequent case of crash: take a lot of precautions not to cut in the hinges (the folds) either along the faces or in the angles nor to make holes or notches through the angles.