BUST: Claw Frozen/Stuck Orbits, Breaking, Infinite Acceleration

[Claw]

Bugs Under Special Test (BUST)

Claw Frozen/Stuck Orbits, Breaking, Infinite Acceleration

This thread is part of a series of community efforts to find the root cause of some of the more difficult to pinpoint bugs in KSP. The purpose of this thread is to for users to collaborate on solving the root of the problem.

Please see here for more details before posting.

Special Note: Please do not post requests for support on this thread. If you need help fixing a problem, please see the other Support stickies linked below.

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Purpose of the BUST threads:

• The BUST threads exist for discussion of the specific topic and for organization of the community of players who are collaborating to dig into the issue. The threads do not exist to answer support requests and any posts for support requests will likely be moved out of the thread.
  
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The ultimate goal of a BUST thread is to end up with a solid bug report that has easily repeatable steps. So if you post information, try to post clear directions on how you came up with it.

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Topic:

The Claw, and all it's wackiness.

Description:

The claw has quite a few problems. Not the least of which is halting itself completely in orbit, causing the rest of the ship to disassemble.

Primary Known Issue Threads:

No specific thread for this, but there are a lot of reports.

What's known:

This is another bug with a lot of sporadic reports. The most recent of which can be found here: http://forum.kerbalspaceprogram.com/threads/100032-Glue-Kraken Other people are able to launch rockets just like the one in the linked post just fine. So what's special about his claw rocket that causes it to fail?

I've discovered that the "glue" portion of the kraken has to do with failure of the craft to fully pack when going on-rails when initiating non-physical warp. This is causing the root to be kinematic while the rest of the ship is non-kinematic. This means that the root part "sticks" and the rest of the ship rips free.

I also believe this thread contains related errors (and likely the same bug in another form): http://forum.kerbalspaceprogram.com/threads/126526

Edited July 29, 2015 by Claw

[Bilfr3d]

Does this include the "Null Reference Exceptions" when clamping stuff? that happens very frequently to me, and I could grab a video and some logs of it happening on a simple ship and I could chuck them up here.

[Claw]

Quite frankly, the claw is by far the buggiest thing and the least understood of the current BUST topics. What will probably work best is if you can narrow it down to what you can figure out, test it, and post the results. Step by step instructions (if appropriate) help so that others can replicate.

So yeah, I'd say anything and everything about the claw is fair game right now. At least until any piece of it can get narrowed own.

Cheers,

~Claw

[Slam_Jones]

Alrighty, here is the craft file for your testing purposes: https://drive.google.com/file/d/0B_FjXR8JXRQZdzVVSkl6QnZZaEE/view?usp=sharing

IIRC, I had: done a launch, reverted to VAB, modified, and launched again, reverted, modified, launched again, reverted, etc etc. Likely no more than 4 or 5 iterations. I had been playing for at least an hour or two at that point, but I can't recall exactly what preceded it.

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(Claw edit: Posts copied from here: http://forum.kerbalspaceprogram.com/threads/100032-Glue-Kraken)

Edited November 18, 2014 by Claw
cleanup

[Claw]

So I copied a post here from another thread to help out with troubleshooting. I did test this craft through several reverts of all kinds and couldn't get the claw to stick in place. I'll keep trying though.

Time warp has also been a common factor, though I'm not sure about reverts. The other thing I remembered is that once this happens to a craft, it gets stuck in the persistence. So it's possible it's getting saved in the files somehow, or at least whatever triggers the bug might be saved.

~Claw

[Oct]

First of all, my apologies for necroing this thread, but I just had this exact same Kraken strike last night in v1.02.

Has any headway been made to solving this or figuring out what it is from?

If the bug is saved to my persistence file, then does this mean that my entire save file will be buggy from now on, or just this single ship? Am I forced to restart if I want to enjoy this game properly now?

Details:

KSP v1.02 Stock.

I had built a ship to mine an asteroid in orbit around Kerbin. It contained a Claw, fuel tanks, engines, and mining equipment.

It launched fine the first time, but I realized that I should have waited for a better launch window to help match orbits. I reverted the flight and time warped for approx 52 minutes. When I went to launch again, something at the top of my craft was frozen/fixed in place at the launch pad. I reverted a few times and kept trying. If I time warped prior to launch, it would stick in place. If I didn't time warp, it would fly no problem. I eventually went to the vehicle tracking station to do my time warp, then to the VAB to launch. Doing this worked fine. It launched properly and got into orbit. I then set a maneuver node and tried to time warp to it. The ship stayed frozen in place while the maneuver counter continued to count down and all other ships in orbit moved as normal. Once it got to zero, it then wouldn't let me time warp again, saying that the ship was under acceleration.

[Claw]

First of all, my apologies for necroing this thread, but I just had this exact same Kraken strike last night in v1.02.

Has any headway been made to solving this or figuring out what it is from?

If the bug is saved to my persistence file, then does this mean that my entire save file will be buggy from now on, or just this single ship? Am I forced to restart if I want to enjoy this game properly now?

Necro is okay if the information in the thread is still relevant, and your post adds substance. Thanks for the description.

No, no real headway in figuring out what causes this one. Your save should be okay except that one ship. However, it will spread if you visit that vessel and have the bug, then visit other ships. The only way to prevent spread once you encounter the bug is to restart the game.

Cheers,

-Claw

[Greg310]

This just happened to me. I made a basic lander with a hitchhiker module as the root part. I landed it on the mun and re-fueled it with a fuel truck using the claw. Now when the lander is in orbit and I try to time accelerate, the root part freezes and all the rest of the parts fall off and drop to the mun. This is accompanied by the nullreferenceexception spam in the debug log.

Its almost like the claw doesn't get removed from the craft properly when its released, like there is still a ghost reference to it. When the game tries to pack the craft for time warp it fails.

UPDATE:

So I restored from an earlier save, and re-enacted everything I'd done. I worked on it a while and tried tons of different variables but I'm not able to recreate the bug. I can't find a smoking gun on what caused it.

Edited June 13, 2015 by Greg310

[LittleBlueGaming]

I've experienced Oct's and Slam_Jones' versions. I want to try getting a null reference exception into a named quicksave, fully stock, and see if we can establish some kind of baseline to work with.

Seems like http://bugs.kerbalspaceprogram.com/issues/2349 will be the key to getting a surefire method of replication going.

[LittleBlueGaming]

I've got a savefile where I can reliably produce a NullReferenceException. It seems to be tied to the '[Log]: Active Vessel is under acceleration (G = 0.829280703246545). Cannot save.' message when using F5. I haven't done this enough to say for sure, but it seems the higher the g-force is when you quicksave, the more likely you'll get the NRE on quickload. Regardless, you can just keep quick-loading from the same quicksave until the error pops up.

Now to figure out how to screw up the claw from here. I've tried a couple things, but no luck so far. Might need to put more vessels up in orbit.

https://www.dropbox.com/s/qq09ntz4ljzxeqj/%5B11%5DNRE.sfs?dl=0

[LittleBlueGaming]

Ok, I've got something even better: https://www.dropbox.com/sh/3e9j7u5ih19ib77/AADsIua2iKg40Qjw3UNjNFALa?dl=0

It's all stock.

1. Load up the game, go to the tracking center, and fly the Claw Debugger 1.
   
2. Turn on RCS.
   
3. 4x physical warp.
   
4. Alternate between A and D to get the ship flexing.
   
5. Quicksave during maximum deflection. Debug log should post an error like this: '[Log]: Active Vessel is under acceleration (G = 0.829280703246545). Cannot save.'
   
6. Quickload, you should get a NullReferenceException error in the debug log.
   
7. 5x warp. The ship should fly apart accompanied by a slew of NRE messages.
   

The first time I tried to replicate this, it worked. The second time, it didn't. What I've found to work consistently is to spam F5 while doing Step 4, so maybe it's an overload of that?

- - - Updated - - -

Output_log: https://www.dropbox.com/s/10nnqpkk8blbf0l/output_log.txt?dl=0

This output log, I had to spam F5 a lot, and go through quite a few quick reverts for it to show up. After it destroyed the ship, I went to the Space Center, Tracking Center, and loaded up the other ship in orbit. Hit '>' and it immediately tore itself apart too, so both ships are in the log.

Edited June 14, 2015 by LittleBlueGaming

[LittleBlueGaming]

And, a little more maybe-helpful information.

The error is in no way, that I can see, attached to a save file. I saved a named quicksave after producing the bug, restarted KSP, and neither the persistent nor the quicksave would destroy craft.

The bugged parts travel in a straight line, they aren't at all affected by gravity. In this instance, my probe core wasn't accelerating very quickly away from the asteroid in m/s, but it also wasn't being pulled by gravity. I have a composite image showing its path over time. I'm guessing its trajectory is just frozen the moment it is bugged and no other forces will act on it. I wonder what would happen if it collided with a celestial body.

When I reloaded to the quicksave(after restarting KSP), which was shortly after the probe core separated from the rest of the vessel, the probe core was again behaving normally, back in a matching orbit around Kerbin.

I can't really think of anything else to test, but I'd be happy to try something if you think it would help.

Edited June 15, 2015 by LittleBlueGaming

[ScienceLion]

KSP Version: v1.0.1.861 Windows 8 64-bit

What Happens: Ship ceases all velocity, camera will get stuck, and the ship resumes to be pulled by gravity.

Mods / Add-Ons: All Stock

Steps to Replicate:

1) Have a ship in orbit with claw.

2) Arm the claw.

3) Fly a different ship into the armed claw.

Result: The combined ships will negate all velocity, the camera is locked into a fixed position, and the combined ships will fall out of view towards the planet.

Workaround: switch vehicles before being captured by the claw.

Save files: https://www./folder/22qg1fuiui9it/KSP_Claw

Fly "Science Station", arm one of the claws, separate one of the tug drones (the stack of drones built around a monoprop 250 tank), fly it into the claw.

Additional testing:

Here's screenshots of debug for when the claw makes a connection. One from whilst flying the probe, the other while flying the ship. Something to note: What causes the forced change in focus? They both say the joint is ready, but one obviously spews NRE all over first.

While flying probe: http://i.imgur.com/tpXDrVM.png

While switched to main ship: http://i.imgur.com/GZof9Fb.png

Edited June 30, 2015 by ScienceLion

[Phibrizo]

I am not sure this is the right topic, but I have encoutered a problem with my last game. I am trying to modify the orbit of a captured asteroid. The orbit itself change, but the asteroid (and my ship) are "frozen' on the orbit.

Look closely these two pictures; my ship is on the blue orbit and it doesn't move...

[federicoaa]

I discovered that the glue kraken, once happened in a save, will affect every single ship, causing some random phantom forces when going into warp and getting frozen into orbit.

First time I discovered the frozen-in-orbit bug was when I captured an asteroid, modified its orbit, and then detach the ship and time warp while focusing on the asteroid.

Probably the issue could be repeated by this way but I haven't had time to test.

[Claw]

I discovered that the glue kraken, once happened in a save, will affect every single ship, causing some random phantom forces when going into warp and getting frozen into orbit.

Yeah, once it strikes one ship it will happen to any other ship you visit. At that point, you have to restart the entire game. If I recall correctly, going back to the menu and returning also doesn't fix it.

LittleBlueGaming was making some progress on this bug, and found some possible ways to trigger it. Although I'm not sure if Blue has found anything new recently beyond what is listed above.

Cheers,

~Claw

[Claw]

Okay. I started working on this bug again tonight.

Thanks to this report and LittleBlueGaming's save game, I have at least one part of this bug fixed.

Steps to Replicate:

1) Have a ship in orbit with claw.

2) Arm the claw.

3) Fly a different ship into the armed claw.

I'm going to try to keep working on getting better repeatable steps for the phantom bending. That way I can test if the fix I just created has any effect on it before digging harder.

If you guys found more info about the phantom forces/bending under timewarp, I'm all ears.

Keep up the good work!

Cheers,

~Claw

[yorshee]

I've had this bug before, I don't know if my experiences will help pinpoint what's wrong but I'll share anyways.

I had a KSP install in 1.0.2 (I think it was that version?) with some mods, the main ones being Extraplanetary Launchpads, MKS/OKS, and KAS/KIS. I made a base on Minmus that mined for metal ore to make into rocket parts which let me launch rockets from Minmus, cutting down the dv requirements to get to places. My mining vehicle was a rover with a claw attached to the front of it that attached itself to the base so I could transfer the metal ore and fuel ore to the converters.

When I tried to launch anything from this base, the Glue Kraken would happen. The root part of the ship would freeze in place when I timewarped whereas the rest of the ship continued on its predicted trajectory, tearing the whole thing apart. It only happened when I timewarped, it would be fine otherwise.

I thought this might have something to do with the claw on the mining vehicle so I detached it before launching. Same thing happened. Then I detached it before spawning it on the launchpad. Still happened. Then I detached it before even building the ship, transferring all the resources to the base before even beginning the actual construction. It still happened!

I did manage to get it to work properly, but only sometimes. I have no idea what actually made it work, it just did sometimes.

I don't think I have this save anymore, I might have deleted it because it was so buggy, but if I still have it would you like me to post it here?

[Claw]

Those are good observations and it matches up with similar reactions another user had. Unfortunately with the add-ons, it really complicates the tracking down of the bugs. Unless, if by chance, the bugged ship happens to be stock. And that reminds me, I should try and dig up that other thread to see if there are any similar events between your two results.

If you find the save, go ahead and post it. It might still be useful or maybe can point to another clue if I can't untangle it from other add-ons.

Cheers,

-Claw

Edited July 15, 2015 by Claw
typo

[Claw]

Ok, I've got something even better: https://www.dropbox.com/sh/3e9j7u5ih19ib77/AADsIua2iKg40Qjw3UNjNFALa?dl=0

What Happens: Ship ceases all velocity, camera will get stuck, and the ship resumes to be pulled by gravity.

Special thanks to both of you. I was able to create a fix for the bug posted by ScienceLion. The one that LittleBlueGaming posted was a bit more difficult (given how hard it is to replicate). I was, however, able to trap the error and prevent it from shredding the ship. This at least buys time for the player to quicksave and restart the game without losing their work.

Cheers,

~Claw

[Vkihyone]

I have had success in causing the error to appear every time I do the following: 1) have a ship with a claw that is deployed on an asteroid (not sure if it can also be triggered by having it deployed and attached to something elsewhere.) 2) go back to the space center load a vehicle with the claw attached and when it's on the launchpad accelerate time by 10x (enable sas if it won't stay stable) 3) bring the time warp down to 1x and launch your ship, the claw should remain in place and refuse to move.

Edited July 28, 2015 by Vkihyone

[Claw]

Thanks for those steps. I'll have to give them a try (hopefully tomorrow night).

Also, welcome to the forums!

Cheers,

~Claw

[Vkihyone]

After more testing I've found out you don't even need to have a claw attached to an asteroid, you just need it attached to another object that is able to be affected by physics i.e. grabbing a rover with a claw on the runway. I think the reason this is happening is because once a claw that is holding another object/ship is piloted/flow etc and time is then accelerated the game freezes the piece and prevents movement as normal but once it is brought to normal time the game fails to bring the claw back into normal time and still sees that piece as accelerated.

[Claw]

The reason the ships freeze is because they fail to pack when going on-rails (which is what happens for non physical time warp). So when coming out of warp, some parts are packed and some aren't. That means they are subject to different physics rules, which causes things to stick, and ships to tear apart in space. (Which I think is what you are saying above.)

The piece I haven't figured out is what specifically causing the pack to fail. That's the key. And if your steps above work for me, then that will greatly speed the discovery process along.

Cheers,

-Claw

[Vkihyone]

Alright I've made three ships to make the bug occur first take the BUST I and launch it on the runway and move it off to the side so you can then launch BUST II. Position BUST I under BUST II and then switch to BUST II, raise BUST IIs' gear and it should grab onto BUST I, to make sure raise the gear on BUST II and BUST I should lift with it. Now go the the VAB and launch BUST III. set the warp to at least 10x for about 5 seconds (5x doesn't cause the glitch when used for a few seconds for some reason). if done correctly the rocket should not go anywhere. here is a link to the files https://www.dropbox.com/sh/pqzsq2jrtjtqs2x/AACQf90k__kHPIvR5lli7w56a?dl=0