I am trying to patch a surface with the "Filled Surface" command and I keep getting this error. I have the area I want to fill completely surrounded by a 3D sketch but it still gives me the error. I have checked to see if gaps in my existing surface could be the problem by sketching an isolated closed piece of geometry and still it gives me this error. Any ideas to this problems remedy will be appreciated. Thank you.
A bit more info is appreciated to give you an answer that is not a shot in the dark.
But have you tried to pick the edges on the surface you want to add the "Fill Surface" to with the selection manager (RMC in the blue box and select selection manager) instead of using the 3D sketch.