[MCPE-32175] existing superflat world has big holes after update

I have this world for 4 years, yesterday I worked on more buildings before finding out about huge holes in my world (didn't affect any buildings).
I copied a backup world from a month ago and everything is normal the first time I play it. I exit to menu and rejoin, holes of same locations appear, and it absolutely ruined my world.

after: https://imgur.com/a/kCF4G

before: https://imgur.com/a/Un0Uq

my beautiful world below😃

Linked issues

is duplicated by 16

MCPE-32049 Giant 40000 block holes Resolved

MCPE-32097 Converted superflat worlds not generating terrain Resolved

MCPE-32168 Superflat worlds don't generate new terrain Resolved

MCPE-32201 preexisting superflat world has big holes after update Resolved

MCPE-32204 Chunk Error / Corrupted World on iOS Resolved

11 more links

relates to 2

MCPE-32493 Flat worlds are not infinite Resolved

MCPE-32892 When generating new chunks in a older flat world, the world generates as "title.info_update.name" Resolved

Attachments

superflat chunks (empty).mcworld

superflat chunks broken chunks.mcworld

Comments 14

migrated 2018-04-05T22:27:24Z

[media][media][media][media][media][media][media][media][media]

CrampedSpider72 2018-04-06T19:13:14Z

Duplicate of MCPE-32135

Arthur Zhou 2018-04-06T19:31:42Z

@CSpider It is not the same as 32135 since
1 my world is superflat
2 no buildings affected
3 caused by update (no platform change)
4 new version even loads holes into my backup world
5 lost chunks are waaaay bigger and my world is now basically a floating island

seems like places I never went to or built on got corrupted

migrated 2018-04-06T19:31:42Z

seems like places I never went to or built on got corrupted

killerbeenl83 2018-04-07T09:52:37Z

Confirmed the issue. Loading a old flat world seems to load chunks fine, until a reload (save and exit and opening the world again) and chunks outside of the existing area fail to be created. (1.2.13.54)
Attached "clean" test world used:

[media]

After the issue occurred:

[media]

4 more comments

killerbeenl83 2018-04-07T11:43:38Z

Additionally:
The issue is most likely caused by the new FlatWorldLayers syntax in the level.dat, not getting updated or recognised correctly as they all seem to have reset to 0 (air). Using the new syntax "fixes" the terrain generation.

Before:

{
   "biome_id" : 1,
   "block_layers" : [
      {
         "block_data" : 0,
         "block_id" : 7,
         "count" : 1
      },
      {
         "block_data" : 0,
         "block_id" : 3,
         "count" : 2
      },
      {
         "block_data" : 0,
         "block_id" : 2,
         "count" : 1
      }
   ],
   "encoding_version" : 3,
   "structure_options" : null
}

After reload:

{
   "biome_id" : 1,
   "block_layers" : [
      {
         "block_data" : 0,
         "block_id" : 0,
         "count" : 1
      },
      {
         "block_data" : 0,
         "block_id" : 0,
         "count" : 2
      },
      {
         "block_data" : 0,
         "block_id" : 0,
         "count" : 1
      }
   ],
   "encoding_version" : 4,
   "structure_options" : null
}

Replacement that works:

{
   "biome_id" : 1,
   "block_layers" : [
      {
         "block_data" : 0,
         "block_name" : "minecraft:bedrock",
         "count" : 1
      },
      {
         "block_data" : 0,
         "block_name" : "minecraft:dirt",
         "count" : 2
      },
      {
         "block_data" : 0,
         "block_name" : "minecraft:grass",
         "count" : 1
      }
   ],
   "encoding_version" : 4,
   "structure_options" : null
}

[Mojang] Mega_Spud (Jay) 2018-04-07T21:33:57Z

This bug has been reported to our internal bug tracker for further testing and a fix. It is scheduled to be fixed in one of the future updates (no specific date can be provided).

[Mojang] Mega_Spud (Jay) 2018-04-07T21:33:57Z

This bug has been reported to our internal bug tracker for further testing and a fix. It is scheduled to be fixed in one of the future updates (no specific date can be provided).

Dan Arndt 2018-04-08T00:47:51Z

Does the same on Xbox one in a flat world.

migrated 2018-04-08T00:47:51Z

Does the same on Xbox one in a flat world.

awesome5185 2018-04-21T09:37:32Z

Hey killerbeen, I replaced the flat world layers data with the one you said 'works' and now it says there was a problem loading this world.

migrated 2018-04-21T09:37:32Z

Hey killerbeen, I replaced the flat world layers data with the one you said 'works' and now it says there was a problem loading this world.

[Mojang] Mega_Spud (Jay) 2018-04-24T15:51:35Z

This issue has been fixed to prevent it from causing holes in worlds again, but unfortunately worlds previously affected may still have missing terrain.

[Mojang] Mega_Spud (Jay) 2018-04-24T15:51:35Z

This issue has been fixed to prevent it from causing holes in worlds again, but unfortunately worlds previously affected may still have missing terrain.