Landed craft bounces on saved game load, KSP 1.3.1

[Gordon Fecyk]

This seems to have been introduced in KSP 1.3.1. Some wheels bounce harder than others, but all have some bounce.

Spoiler

 

The large gear seems to have the least noticeable bounce, but it's quite noticeable at Minmus. The others are very noticeable back at KSC. The small gear seems the most stable.

To avoid scrolling down, here are current bug reports filed on this problem. Please upvote these.

https://bugs.kerbalspaceprogram.com/issues/16159 <- Surface collisions on physics start

https://bugs.kerbalspaceprogram.com/issues/16090 <- Related to prerelease bug #15796 Non-active vessels jumping on load still happening on 1.3.1

A workable workaround to this problem, courtesy of @whale_2

 

Edited January 9, 2018 by Gordon Fecyk
Added link to add-on that works around problem

[Galileo]

I have noticed this as well. It’s not just upon game load. You can just choose a craft from the tracking station. The craft will jump each time  how this got past QA is crazy to think about. Not just wheels either, but landing gear as well

Edited October 16, 2017 by Galileo

[Kerbinchaser]

I noticed this back in 1.1.  

[adsii1970]

2 minutes ago, Lo Var Lachland said:

I noticed this back in 1.1.  

It has been present since .90 and that was to be "Beta than ever!"

[Gordon Fecyk]

11 minutes ago, Lo Var Lachland said:

I noticed this back in 1.1.

The dramatic bounce with the medium landing gear isn't in 1.3.0. That craft is Matt Lowne's Blunderbird 6, which I've managed to fly to the Mun and back ^[1] a couple of times. Last night was the first time I took it for a spin in 1.3.1, and it bounced high enough off the munar surface that I could get back to orbit with less fuel.

[1] I added one more liquid fuel fuselage to the rear and clipped the LV-N into it a bit.

[Galileo]

The bounce has been around for a long time, but the insanely high bounces just showed up in 1.3.1. Rather unfortunate.

[unclejace]

I am playing the most recent version of KSP. Since the update to 1.3.1, I find that my spacecraft bounce up off celestial body surfaces right after "physics easing in progress." This has happened on Dres, Ike, Pol and Gilly. In all instances, the craft were stable before a game save and/or navigating to them in the tracking station. It has happened both with and without drills deployed. Most recently, I landed on Gilly and saved my game with my craft stable and everything shut down. When I reload the game and go to this scenario, the “bounce” of the ship after physics easing launches my spacecraft back into orbit. Frustrating to say the least.

 

It also makes no difference whether landing gear is deployed or not.
 

Edited October 18, 2017 by unclejace

[Galileo]

Has anyone made a legit big report yet?

[NateisKerbal]

Maybe it's not a bug. They may have thought the current bounce was unrealistic. Just pointing that out.

[Galileo]

9 minutes ago, NateisKerbal said:

Maybe it's not a bug. They may have thought the current bounce was unrealistic. Just pointing that out.

Have you not seen the “bounce”? Landed on anything, completely shut down, and crafts leap off of the surface upon load. I would watch the whole video posted above to get an idea.

Edited October 18, 2017 by Galileo

[NateisKerbal]

1 minute ago, Galileo said:

Have you not seen the “bounce”? Landed on anything, completely shut down, and crafts leap off of the surface upon load. I would watch the whole video posted above to get an idea.

Oh wait, I'm running 1.3. Sorry, yeah that is bad. Someone should report this.

[Gordon Fecyk]

21 hours ago, NateisKerbal said:

Sorry, yeah that is bad. Someone should report this.

https://bugs.kerbalspaceprogram.com/issues/16159 <- Surface collisions on physics start

https://bugs.kerbalspaceprogram.com/issues/16090 <- Related to prerelease bug #15796 Non-active vessels jumping on load still happening on 1.3.1

Just upvote these, so there's no need to submit duplicates.

Edited October 19, 2017 by Gordon Fecyk
Found more reports

[Fwiffo]

Happens even without landing gear, just plain old strut legs.  My Minmus craft in my savegame is unusable :-(.

Also happening on exit from timewarp.

I can't figure out how to upvote the bugtracker.

Turning off physics easing ("ease in gravity") doesn't help.

Edited October 23, 2017 by Fwiffo

[Prenerk]

I can confirm. Anytime I land a craft on any body and go into any level of warp or switch to another craft and come back, the ship will explode after physics easing starts. It looks like the physics easing causes the ship to clip into the terrain and then explode when it tries to 'bounce' out. Absolutely maddening.

[invision]

also happens in 1.2.2

ive lost a few ground vehicles because they load and bounce which sometimes makes them explode, this is one of the reasons i dont build  bases anywhere.

[Anth]

It was an issue before to a lesser degree...but this wasnt happening in 1.3.0 to the same level as it was happening in the 1.3.1 prerelease,

Last status I saw for this bug within the prerelease bug reports was that it was being worked on. Now that bug report is gone.

Even though it was someone else that submitted it for the prerelease...I submitted another one into the normal version of KSP Bug Tracker when 1.3.1 went official

Others are responding and confirming here https://bugs.kerbalspaceprogram.com/issues/16090

Edited October 26, 2017 by Anth12

[XLjedi]

I hope this one gets fixed fast!  ...my large SSTO with refueling gear vaults off Minmus a good 20 meters coming out of accel time.

In the meantime though, I seem to have found a new Kraken assisted takeoff mechanism for low gravity worlds!

This is pretty bad...

 

Edited November 5, 2017 by XLjedi

[kari1393]

I noticed this issue too, after upgrading from 1.3.0 to 1.3.1.

My Minmus mining rig that uses Mk2 landing legs became unusable, launching twice it's height upward on being loaded.

[dark_reef]

I just did some testing and I dont think it is a bug in the base program (I swear it happened in the non modded version, but I am probably wrong). I think it is one or more of the mods. Does anyone know of any known issues with this problem and a specific mods? I will start testing but it might take a while. I think it might be Joint Reinforcement but still need to test.

Edited November 14, 2017 by dark_reef

[Ultimate Steve]

Yeah, this is happening to me as well. I was flying something to the polar saucer, then flew something else, and I loaded the first plane. It jumped about twenty meters into the air.

[dark_reef]

Do you have mods installed (or had them installed at some point)?

I am doing some testing and it does not do it with the stock for 1.3.1 in sandbox, that is as far as I have tested so far, but will spend the rest of the day at least narrowing it down to what is causing it so I can get the info to the developers.

Here is a video I found of the exact problem: 

 

Edited November 14, 2017 by dark_reef

[Gordon Fecyk]

7 hours ago, dark_reef said:

I just did some testing and I dont think it is a bug in the base program (I swear it happened in the non modded version, but I am probably wrong).

Don't sell yourself short. My video example is in an unmodded game.

[dark_reef]

I can confirm it is a mod that is breaking it. Here is how I tested it.

1. Download new clean install from Steam, created a mining ship and flew to Minimus and landed on the frozen ocean. F5-F9 No problems. Time warp over and over no problems.

2. Took the save game from the working install and put it into my modded version of KSP. Loaded up save and Loading save and timewarp will either destroy landing gear or bounce it about 30 meters in the non air.

3. Took the clean install that was working and download the same mods (via ckan). Loaded up save and again went to SHIP!

4. Resaved game in install from step 3 (broken) and copied it to the install from step 1 (working). Loaded it up and here is where it gets interesting. It bounced on load . BUT...BUT...BUT then it was fine. After is was back on minfirma I resaved, loaded - no problems, and was able to time warp no problem.

5. Took the Broken copy from step 3 and manually removed all mods from the GameData folder (deleted everything but the Squad folder). Loaded up KSP and guess what... Problem gone.

So it IS a mod, which one or ones I do not know yet but will continue to test. I am just going to start deleting them until it starts working.

I did notice what might be happening, after my mining rig was on its side I tested time warp and when coming out of warp the ground would drop 1 meter. The altitude would be 2 then after time warp it would go to 3 then the ship would settle back to 2.

I also noticed that even the "working" versions still do it but to a degree that is so minimal that you only notice it if you zoom in on the landing gear when loading or time warping.

If anyone knows what might be happening please let me know as I want to play the game not troubleshoot fixing it.

It would also be nice if someone could also reproduce it on their end. I could provide my whole install with saves and mods if a dev wants to take a look at it.

Edited November 13, 2017 by dark_reef
Added more info.

[dark_reef]

Found the problem mod. It is Ven's Stock Part Revamp. If I remove it from my test install everything works fine.

It only took me about 6 hours of testing as I have about 60 mods installed.

I tried to remove from my career install but it removes basically all my ships. I guess all my ships have stock parts, go figure.

Does anyone know how to report this as a bug or is there a way to change all the parts on my ships in the save files so I can continue playing?

[XLjedi]

@dark_reef appreciate you spending time swapping out your mods to see what might be causing it.

...and here's my 5 minute confirmation that it has nothing to do with a mod. 

1. Renamed my game folder
2. New vanilla Steam install of 1.3.1
3. Put a craft on the runway
4. use accel time, and...

Ker-BOUNCE!  ...it's a 1.3.1 Ker-BUG!