Error encountered while analyzing a twisted and tapered wing?

The following error was encountered while trying to get the wake behind a twisted and tapered wing,

"Warning:
edge:Skipping wake, must be attached to 2 walls, with identical normal orientation".

If the wing is twisted and tapered, how to solve for wake?
Please help me out!

Faces need to be connected

Assuming you are using the panel method as in the tutorial "Flow Over an Airfoil".

The faces that make up your wing have to be attached to each other through edges, such that each each edge is connected to 2 faces. If you are assuming symmetry then the edges that lie directly on the symmetry plane can be attached to only one face.

For the panel method to produce lift and pressure drag you need a sharp trailing edge to attach a wake.