So why does this not always work? If you create a plane and a Sketch why can this not be done? A problem I have run into a lot. It errors out a lot.

All I trying to do is fill that top I tired to create a sketch will not knit, tired to sweep it will not knit, Tired boundary surface will not knit. Basically I have tired 5 different things and nothing seems to work. Again auto cad mach. not a problem two seconds and its fixed, but again working with solidworks must come up with a work around.