What is a C2 Patch?

"What can you do with missing edges?"

Of it's Assembly patterns I have an answer for this. I will post it Friday after work. Let's make sure what is the issue?

I am not sure if this is the issue you are having or not, At work we have problems of assembly level linear patterns losing their edges. The pattern stays mainly intact. The feature tree displays an error with the pattern. When you edit the pattern, sure enough there is no edge for the pattern to follow. My co-worker found a great way to fix this issue. Add 3 axis’s to the part, based off of the three primary plains, name them “X-Axis”, “Y-Axis” and a “Z-Axis”. Then just edit the part and add select the axis you need, This will work for most cases unless your edged is not parallel to one of this axis’s. We have added this axis’s to the part “.sldprt” and assembly “.sldasm” template files. Any new part or assembly created automatically start with the 3 primary planes and 3 axis’s.

Just because a feature "does not work" when you try it, this does not mean SolidWorks will not do it. It always tries to tell you why it would not work. As you get familiar with it you start to understand what these (sometimes cryptic) messages mean. What prevented you from using 2 edges? Were there any error messages? Did you try converting one of the edges into a "curve" and use that instead? Were you trying to use the edge/curve as a path or as a guide curve? If a guide curve, then you need to pierce point the sketch to that guide curve. You also need to make sure that there are no constraints in your sketch which will become invalid as the sweep progresses. I hope these questions will help. Like I said, sweeps are difficult. I recommend getting expert on lofts first before you try sweeps. They are easier to understand and often can achieve what you want, although there are more steps involved in setting up a loft.