Maybe you could identify what you're trying to do. I know you said "sweep', but there isn't anything set up to make a sweep. Plus, SolidWorks cares if you make a sloppy sketch. It really wants you to be precise with stuff. Minor things like tangency, curvature, self intersections during sweep, it all makes a difference to SolidWorks.
Can you identify what you are trying to use as a path and sections?
Also, it might turn out that a sweep is not really what you need. The outside shape looks to me like an extrude with a fillet, and then some kind of feature on the back. It could be just a boss, a fillet and a cut. Not sure what you are trying to accomplish.
If you are trying to sweep profile of sketch13 using sketch12 as the path, it won't let you. The radii in sketch13 are larger than the ellipse & would create a self intersecting feature. If you eliminate the 2 ellipses you can create a sweep.