Unable to undock ports attached in VAB

[teddy_beer_maniac]

Hello, I encountered an issue with KSP 1.1.2 (running on Windows, tried both 32 and 64 bit) in which if I attach two docking ports in VAB, there won't be an Undock option during a mission. If I choose the Decouple Node option, then the ports will be still stuck together, despite game showing there being two separate spacecrafts. If I then go to the Space Center and back to the vessels they'll either dock and after that ports will have the Undock option, or there will be lots of uncontrollable spinning and exploding. At first I thought it may be because of mods that I have installed, but I was able to reproduce the issue on a clean install with a new save. I'm wondering if I'm doing something wrong, or is it a bug, because IIRC I created vessels this way pre-1.0 and they worked as intended.

Craft 1 Craft 2

[Tarheel1999]

Try decoupling in space. It works differently when there is no gravity. 

[teddy_beer_maniac]

The screenshots are just an example from a new save. I first encountered this in space.

[Tarheel1999]

Understood. You can't "dock" things in the Editor. The "decouple" option is what you get when you stack something on a docking part in the Editor. When you hit decouple in space the parts separate and slowly drift apart. Have you tried time warping to speed up the drift? This works fine in my modded install and so it is probably an issue with your ship design or your install.

The camera/exploding parts issue is probably due to precision errors. If the decoupled vessels are literally on top of each other, bad things  will happen when you reload the scene. 

[teddy_beer_maniac]

Thanks for the explanation of how docking ports work in the editor. I don't know why my brain decided to treat the "Undock" option not being in the menu and the fact that my ships were stuck after decoupling as one "issue". As for the latter, I still don't know why vessels were glued together, because when I strapped some boosters to the part I wanted to undock in orbit and tried doing the same on the launchpad it separated correctly.

I feel like after 250 hours in KSP I still know next to nothing about the game...

[Claw]

Yep, what Tarheel1999 says sounds about right.

On the ground, when decoupled, they stayed stacked because there's not a lot of force that separates them. Leaving and coming back then resets the docking port states, so they will end up docking while on the pad.