How to select chain loop on chamfer

[Karol-Or]

I wanted to chamfer a poligonal faced part, but had to select the edges one by one.

The Edge Chain buttons were grayed out, why?

[JDMather · Accepted solution]

The dialog box has a tool tip that explains edges must be tangent to select chain.

 

Once you pick an edge that is not tangentially connected these button are not relevant.