Rover is stuck in the air after decoupling

[CaptainCaptain]

I have landed a rover with a sky crane on Duna. The sky crane is connected via a decoupler with the rover. After landing, when both parts are still coupled, everything works fine. The rover is fully functional and the sky crane also works as intended. Now when I decouple both part from each other the following happens:

1. My rover is stuck in the air (or sometimes Duna)
2. My rover is always showing a surface speed of 3 m/s
3. All inputs generate the right response on the UI but for example the wheels won't move
4. The time is reset to 0

You can find some screenshots of the problem here: https://imgur.com/a/6dQeMGN

I have tried different locations, different decoupling methods, I tried decoupling with the sky scrane as control point as well as the rover as control point, etc. but the bug always occurs.

What's happening here and is there a workaround for this bug?
 

[OHara]

This could be the bug that appeared in version 1.11.0, where physics stops working if the 'root' part of the dropped craft
(the part connected to the decoupler that releases the rover from skycrane, and skycrane from its mothership)
is one of  {cubic strut, octagonal strut, FL-A5 adapter, BZ-52 radial attachment} or possibly a small part from a mod or DLC.

If that is the problem, you can avoid it by rebuilding your rover-to-skycrane connection to make some other part the first one connected to the decoupler.

If you are on PC and have installed any mods, you likely have Module Manager with one of them, and this MM patch text in a *.cfg file will change the rules of KSP to simulate full physics on the strut, etc.:
@PART[*]:HAS[#PhysicsSignificance[1],#attachRules[*,*,1,*,*]] { @PhysicsSignificance = 0 }

(The bug on Squad's tracker is #26926 and #27323 but we can no longer see the bug reports without creating a login there as we would to report bugs.)

Edited June 13, 2021 by OHara
and from the description and screenshots, it does seem to be that bug

[ShuttlePilot]

This has happened to me too. It's a pain in the REDACTED really. I don't know what is the problem or anything, but when I try to land my rovers they just get stuck in the air. Also this happens only specifically on Duna and that makes it even stranger. I tried using cheats to get it down, I tried reloading quicksaves to landing, I tried cutting the parachutes, everything that was possible was tried, but nothing has helped. Also a note: One time I tried to land my rover on Duna it got stuck in the air while showing the surface velocity as 256 m/s. and also that 256 is very suspicious, isn't it? I can't seem to help you, but I can tell you that you're not the only one.

[jimmymcgoochie]

I think the problem is that the root part of the rover is a physicsless part which confuses the whole game. Re-root the rover/skycrane assembly in the VAB so that the root part is the rover’s probe core and then cheat it out beside the broken one, then delete the broken one.

[ShuttlePilot]

5 hours ago, jimmymcgoochie said:

I think the problem is that the root part of the rover is a physicsless part which confuses the whole game. Re-root the rover/skycrane assembly in the VAB so that the root part is the rover’s probe core and then cheat it out beside the broken one, then delete the broken one.

Not necessarily in the VAB/SPH. You can do it in-game

[Geonovast]

37 minutes ago, ShuttlePilot said:

Not necessarily in the VAB/SPH. You can do it in-game

Care to tell how?  I've been wanting this for years and it seems to be one of the few VAB/SPH functions missing from the in-flight construction mode.

[jimmymcgoochie]

18 minutes ago, Geonovast said:

Care to tell how?  I've been wanting this for years and it seems to be one of the few VAB/SPH functions missing from the in-flight construction mode.

I’m interested to know this too. @ShuttlePilothow do you re-root a craft in flight?

[ShuttlePilot]

On 6/14/2021 at 7:12 PM, jimmymcgoochie said:

I’m interested to know this too. @ShuttlePilothow do you re-root a craft in flight?

Oh re-root? Yeah, sorry. I was mistaken. I tought that you we're descirbing the autostrut function for a while.

[Dr. Kerbal]

I would reload a quicksilver, revert the flight to launch, or revert to the VAB or SPH and rebuild the craft and test it. 

[ShuttlePilot]

1 hour ago, Dr. Kerbal said:

I would reload a quicksilver, revert the flight to launch, or revert to the VAB or SPH and rebuild the craft and test it. 

Oh the Doctor Kerbal is here! Anyway it's really that simple, but I don't get it. What if the OP made a very ultra detailed replica with 800 parts of let's say, Curiosity rover, then things start to get real.

[Dr. Kerbal]

9 hours ago, ShuttlePilot said:

Oh the Doctor Kerbal is here! Anyway it's really that simple, but I don't get it. What if the OP made a very ultra detailed replica with 800 parts of let's say, Curiosity rover, then things start to get real.

Ah ha. This happened to me too. I would recommend saving every craft you make so in case weird bugs happen you can fix them up or just fix the clipping.