I have an error on a Boss-Extrude on an 3D sketch that won't rebuild (The sketch contains an open contour).  At this point, I just want to delete the damn feature or rollback the history but there seems no way to do it (no delete option and I can't roll it back).  Is there a way to force a delete?

I'm trying to learn solidworks and this is a tutorial to extrude some text. Any advise on fixing the open