Shadows reply is about the best way to find/fix the issue.
It requires everything but the wok to be hidden, then you look from beneath the wok, preferably directly as in 180degree from the top. Meaning that you move your camera view directly under the wok and look directly upwards. By default, NOTHING should be visible, IE no face should show normally from this view. If you have a face that IS showing, that is likely the one that is failing in CM3.
It can happen if you accidentally double face the object (wok) or have copy/pasted objects together to get your wok from copies of other objects etc, and missed a face here or there when deleting the extras and attaching everything together. That is typically how I generate a wok, I just duplicate objects and attach them, then delete the faces I don't need, also remembering to weld all the verts of course '> The double face can happen fairlly easily is you are using Veltools as it has a button or three that will do that sort of thing for you automatically but they can also easily be hit when you didn't intend to do so.
Other instances of something like this is where are particular face is actually overhanging, IE a backwards sloped wall type of thing.
P.S. CM3's error report used to tell you exactly what face on what object was causing the issue... at least I thought it did I may be thinking of the sanity checks for that though. I know that the wok sanity check will tell you exactly where it breaks by face number or vert number.