Some chunks in the same world seed seem to have different versions

I provided two more screenshots. This time a chunk nearby the wall (same seed of course). This one also has two different versions. In this particular case I loaded the world 10 times (new game), waitewd till the chunks loaded and when to the location. 2 of the ten times the wall was different (with dirt, first two screenshots), 6 of the ten times the beach looked different (new screenshots)

Now that cubethethird has reproduced this, can this bug be confirmed? I don't know what the procedures are though. 🙂

It has already been marked as confirmed.

Yes it is, sorry!

...that was me after @unknown's request to mark it as confirmed and before @unknown's comment that it's already marked ...

Bug tested with 14w30c. Eight attempts the proper coal wall generated. The ninth attempt the coal wall looked like a dirt wall. So bug is still active.

Confirmed for

• 15w37a

Could you please add the teleport command: /tp -189 65 94 0 0
And there are two minor mistakes, where once you wrote "coördinates" and the seeds provided are identical

I recently found this blurb on the wiki which may explain this bug:

Structures are generated for a given chunk after the terrain has been formed. The chunk format includes a tag called TerrainPopulated that indicates whether structures whose point of origin is in that chunk have been generated. If it is false or missing, they will be generated again. Structure generation is based on what is already in the chunk, so (for example) flagging a chunk that has already been populated for repopulation will approximately double the amount of ore in it.

When structures are generated, they can spill over into neighbouring chunks that have been previously generated. Thus, a tree at the edge of the generated world (and probably only visible using external tools) may be overwritten by a lake before you reach it. It is also theoretically possible for two worlds generated with the same seed, from the same version of Minecraft, to differ slightly depending on the players' travel routes, because the order in which chunks are generated may determine which of two conflicting structures will overwrite or suppress the other.

I suppose this is based on approach direction?

@unknown, yes, this is very likely based on the direction the location is approached from. See this comment from MC-203758 for a recent example of this bug. However, that example doesn't seem to work in 21w11a because world generation has changed and the geode does not overlap a mineshaft at that location anymore.

Is this issue still happening?

Yes, see [MC-225206]

Can confirm for 21w20a per [MC-226027]

Can confirm in 1.17.1 Release Candidate 2; came across this bug while trying to reproduce MC-231198. This makes reproducing some issues harder, because teleporting and flying to a location seems to generate different versions of the same chunk for whatever reason.

Can confirm in 1.17.1.

Can confirm in 21w39a unknown if present in the End, present in the Nether.

This bug has been in the game since its origins. It's caused by chunk loading order - if you load a chunk with a mountain in it and then load a chunk that's supposed to spawn a tree touching that mountain, it won't spawn. If you generate the tree chunk before the mountain chunk, though, it'll appear in-game.

Can confirm for 21w43a

Can also confirm in 21w43a.

Overall, it can be stated that this issue is much more common than anticipated. MC-238073 seems to have covered up this issue making it harder to detect. As shown in screenshots, chunk consistency is now higher, with a few chunks being consistent across all images. However, this issue is much more pronounced than before 1.18. It is likely that the severity of MC-238073 was in part caused by this issue. This can be proven with the nether as its terrain generation is unchanged with the small instance documented being one of the few examples for this issue. However, the Overworld is covered in this issue making it incredibly easy to document.