Wall does not support profile Sketch as it is not a straight wall; or is tapered; or it is an old curtain wall; or it is an infill wall; or it is a replacement curtain panel. -or- Wall already has a sketch.
Remarks
The loop of the sketch cannot be obtained until regeneration. To regenerate the document use Regenerate.. To edit the Wall profile use [!:Autodesk::Revit::DB::SketchEditScope].