No idea why, but I'm consistently getting some carts that forget they are linked after a game restart.

How?

Links should be stored in the persistent entity NBT data and point at the other entities persistent UUID.

This is all handled in LinkageManager.java.

I mean how to reproduce it. Does it happen when you leave the chunk it's in?

Restart game, wasn't enough to reload world.

Could you state the steps to reproduce it more clearly?

Link a bunch of carts, quit the game, start the game, load world, see broken links. That's really all there is to it.

Can this still be reproduced?

huh maybe the game does not fully save all when quite save is pressed???

are all the entities properly registered in the registries? if not that could cause nbt to not get saved

This is still the case with beta 2!!!! It forgets ALL links when chunk unloads

Then it looks like a bug of storage of Railcraft NBT tags.

In my opinion, this is probably an issue regarding NBT loading because the cart linking state always saves when a link is created or broken.

For me, I cannot reproduce it. I linked a bunch of carts, walked away, and went back. I saw those carts still linked. Quitting the game does not work either.

@liach probably when chunks unload? you may need to walk away far enough.

Like 10000 blocks? Or just 1000 block? I tried to go 700 blocks away and return, and the carts remain linked.

think like 10000 blocks...

Will try later. Thanks for your info.

confirmed

Does this happen with certain types of minecart or all?

May this be a dupe of #585?

Experienced the same problem in the current version (10.0.1):
https://www.youtube.com/watch?v=NRi82tY2J1A

• Spawn carts and link them
• Exit world
• Reload world
  -> Carts unlinked

I tried to reproduce it in a new world. Sometimes it did work as expected, other times it did not.
Tested it at world spawn and 10,000 blocks away. Doesn't matter if I logged out right besides the train or far away. The result was the same. (Tested in singleplayer, no idea about multiplayer).

@Ruuubi Cannot reproduce it, but I can see some weird behavior in cart physics.

Have we come up with a solution?

Haven't looked at it recently.

Might this relate to the loading of nbt data instead of the stroage of it?

This issue has been observed several times on the official Railcraft server.

@CovertJaguar Can I mark this as can't fix?

No, I have a possible fix in the wild being testing right this moment.

https://minecraft.curseforge.com/projects/world-utils#title-7
We should try with this mod.

@CovertJaguar This issue still exists, confirmed on the patron server.

The Shunting Aura should provide the info necessary to fix it.

Can we try with dormant chunk cache disabled?

Identify the problem first, then start looking for solutions.

Closing since we haven't reproduced this in a long time (especially on patron server) and some fixes were already pushed.