Ships won't merge

[JMBuilder]

I'm trying to connect an orbiter in the VAB to a large spaceplane from the SPH, but something's wrong. The node on the ship that I load in is invisible and refuses to connect to the node on the already present ship. Am I doing something wrong?

[Tex_NL]

Without more info all I can say is Yes, you are doing something wrong. But what exactly remains to be seen.
Post some pictures of what you're trying to do and where you fail. Only then can people see the problem.

[swjr-swis]

When you 'merge' a whole independent ship, that was not created specifically as a subassembly, the game will use the root part of that ship as the attachment point. That root part may not be the part with the 'free' node you want to use. And if that root part has no free nodes of its own and is not surface-attachable, you won't be able to attach it rightaway.

So just click in the air to 'park' that ship a moment. 1.1 introduced the ability to re-root unattached assemblies. Use this to your advantage.

Use the Root gizmo on the unconnected ship, to select the part you want to connect with. This can be one with an actual free node (eg a docking port or the open end of a tank, etc), or a part that can be surface attached. Basically you force the game to redo the part structure so it becomes a proper subassembly with the part you want to connect with as root. Now try and place it and you'll see it'll work.

Word of warning though: the game will have very odd ideas sometimes about the orientation, so don't be too surprised if it looks like it's attaching all wrong. Sometimes it's pretty darn impossible to convince it to attach 'right', but if you ignore it and place it anyway when it turns green, you should be able to move it in the right position with the rotate/offset gizmos.

If the part you want to be root is somehow already the root of that ship, just make a random other part root first, then back to the one you actually want. Sometimes the game needs to be forced to 'redo' the root for it to work.

 

Barring all that, pics and/or craft/save files if it's still not working and you want more help, otherwise it's just blind guesswork.

[JMBuilder]

BINGO! It worked.

[Claw]

You should also reroot the merged craft (or subassembly) by pressing "4" while you're still holding it.