Docked spaceplane causes station to fall out of orbit completely?

[Tassyr]

So yeah, I made a station. Docked several parts to it. A total of three mod parts (the smartparts mod so I could have a certain cone ratio for the adapters.) on the station and none on the plane, plus mechjeb.

I finally figure how to make spaceplanes that can reach orbit. But now... when I dock that station and ship, this happens. And it's not like there's a colossal THUNK of impact, it's as if there's constant thrust being applied! Help?

And I can't rotate the station any more, nor does it consume any resources. Help?

[Padishar]

Assuming your station was in a roughly circular orbit at the altitude it is at in that screenshot, then it would have to be a really big impact in quite an odd direction to change the orbit by that much. You say it is like there is constant thrust being applied, so does the orbit keep changing? Is there a claw on either of the vessels? They are known to cause all sorts of odd issues that could look like this...

There have been quite a few reports of issues like this recently but without better (i.e. more reproducible) reports, it can't really be investigated easily. Can you supply a quicksave file from just before you dock the spaceplace to the station (and confirmation that smartparts and MJ are the only mods)?

[Major999]

Was there a cargo bay on the space plane? Often if the contents of the cargo bay clip into the cargo bay doors, Weïrd forces will start to affect the space station. It happened with my own, causing it to slowly change it's orbit inclination. open the cargo doors, or undock the spaceplane, and see if that helps.

[steve_v]

Congratulations, you have constructed your first kraken drive!

On a more serious note: known issues with KJR, if you're running it, or part clipping - especially landing legs.

[wasml]

I had similar problems at one point - craft that I couldn't control spontaneously accelerating without using any fuel, pices of a craft falling off and heading for kerbin. I don't remember where I first saw the suggestion but I deleted all the .cfg's in GameData\MechJeb2\Plugins\PluginData\MechJeb2 except for mechjeb_settings_global.cfg. Problem went away. One thing to note - there were close to 255 .cfg's in the directory - the person who had found the solution mentioned they had around 255 cfg's - might be relevant or it could be coincidence.