Not sure what's going on here.

[BagelRabbit]

To make a long story short, this.

Now the craft is corrupted, and there's no way to repair the damage. I hear that this bug is relatively well-known, but I can't find an example of it on here. Could someone please help me understand what happened?

Thanks!

[Tw1]

I have also lost craft this way. Do you get endless duplicates when you try to move the shiny bits? That happens sometimes.

When this happened to me, I split what I could of the craft into subassemblies, and started again with a new file.

[Claw]

Yeah, this is a kind-of well known problem although not really documented anywhere in particular (as you have said).

There are 3 general ways this can happen:

1. Symmetry within symmetry - When you place symmetric parts on a parent, then grab that parent and make symmetric parts with it onto another parent. I do this a lot and it's not a problem if you're careful.

2. ALT+F-12 clipping in conjunction with symmetry. - This one is more dangerous. It can happen without symmetry, but it occurs much more often when symmetry on.

3. Use of Undo (Ctrl+Z). - I pretty much never use this because it's so unpredictably buggy.

Based on how your craft looks, I'm guessing you made use of the ALT+F-12 clipping option. Debug clipping can be problematic and sometimes when clipping coupled with symmetry when you are applying things to one node. When removing parts and putting them back with these options enabled, sometimes phantom parts are created that don't appear attached to the craft (i.e. they are far away), but the are technically connected by the internal part structure. That's why you get floating engine pieces that are firing. Also, sometimes using undo while there's a part hovering off to the side can cause similar events where parts become reattached even though they are floating off to the side.

Unfortunately, once this has happened it's a mess to clean up. And with phantom parts, you can't always be sure you got rid of them all.

What I usually do if I'm going to make use of these kind of options is to save periodically with different craft names. Then you can use the load screen to let you know if something weird is happening. When you bring up the load screen, it tells you how many parts the thing has. If it's indicating a change of a lot more parts than what you actually added, then you might have a problem. With multiple versions, you can backtrack without losing too much ground. If I do make use of option #2, I will turn on clipping for the minimum amount of time necessary, then turn it off immediately. I've had a lot fewer problems this way.

Hope that answers your question.

Cheers,

~Claw

[Kerano]

Yeah, I've just got this too. Building a new spaceplane with unmodded 0.25. Detached symmetrical sides, added an extra fuel tank to the middle section to balance the mass better, clicked sides to reattach them, and the bug was triggered.

Upon exiting the SPH and reloading my craft file, this was the result. Exiting the whole game and reloading the craft in the SPH confirms it is permanently broken... shame, will have to revert to an earlier version.

Notice the COM and centre of thrust seem to be calculated exclusively from the detached section, while the centre of lift is calculated exclusively from the original section. (Or maybe the detached section has just been duplicated multiple times and is overlapping itself, judging from the number of engines in the sidebar.)

In case it's useful - craft file.

Edited October 8, 2014 by Kerano