Docking port orientation

[Fwiffo]

Can someone elucidate me as to precisely what condition causes the following warning in the Editor?

Docking port is not facing or attached the right way. In this position it is considered useless.

I have a couple weldments that include docking ports.  The port it's complaining about docks fine (I tested it), with the minor exception that the distance is incorrect if it is the one being controlled.  I've tried reorienting the port every which way, and also setting it as the root part in my preweld.  I've also tried to edit the referenceAttachNode.  In fact, whenever I attach a docking port to my weldment, it always seems to complain about this.  The only way to resolve is to make the part with the docking port in it the root part in my final craft (at which point it complains about the part with the other docking port)

I need some more understanding of exactly what the game looks for to trigger this message, as it doesn't seem to be what I'd expect.

EDIT: Does referenceAttachNode even still do anything anymore?

On 5/2/2015 at 9:47 AM, toadicus said:

In previous KSP versions, ModuleDockingNode would use referenceAttachNode to go get the transform used for docking; that's no longer the case. They are still used for determining "preattach" behavior when you put two ports together in the editor (and maybe some other things; it's really hard to tell).

EDIT2: After some more research I realized this might be more appropriate in the welding thread, and posted some related questions here.

Edited November 7, 2016 by Fwiffo

[Fwiffo]

Figured it out.  It always warns that when you put two docking ports together (in any orientation) with nothing in between them.