I have a very simple 3d sketch which looks like a wedge. I just want to loft/extrude the shape to a solid, but am getting errors each time I try. I understand how to loft two faces together, but this sketch shares an edge. I have tried to use every combination of the group select, but get errors each time about the groups not all being closed or open, invalid geometry errors, "cannot knit sheets together" or that I need to select a continuous group. I don't know why this is so difficult, but would someone be able to have a look at my file and let me know how to do this please?