So I loaded up a copy of my main survival world in the latest snapshot to play around with bees, but after that I forgot I was in the snapshot and did a load of work, so now I don't want to revert to the 1.14.4 backup. However, it would seem the following bugfix causes problems:
MC-158988 - Minecraft will remove up to several hundred chunks per region if region file isn’t exact multiple of 4096 bytes
When I load up the world in 1.14.4, everything I've built gets erased because the chunks get regenerated. This is because the snapshot doesn't lock the region files to an exact multiple of 4096 bytes anymore. Does anyone have an idea of how to revert them back? I opened a region file with a hex editor, but unsurprisingly that wasn't much help. Would it be as simple as adding null characters until the file is an acceptable size? I don't know enough about the region file format.
You might be able to open the snapshot save in MC Edit, copy out the chunks you changed, then paste them into the save from 1.14.4, make backups of everything first, of course! It all depends on if MC Edit can read a snapshot save or not, I don't think it's been updated in a while, I haven't checked.
Rollback Post to RevisionRollBack
D_B
To tell them how to live is to prevent them living.
Have you verified that your region files aren't multiples of 4096?
I think that moving save files back to an earlier version always has caused problems, mostly because of new blocks that the older version doesn't recognize and therefore thinks the chunks are corrupted and regenerates them.
So I think you'll probably just have to continue in 1.15, though there's no real guarantee that the final release will be fully compatible with the snapshots.
--
You might be able to use the structure blocks to save your builds, after removing any new blocks like hives, and import them to 1.14 that way.
I wouldn't know, I've never looked at how the structure blocks work.
Be sure to make backups at every step!
Good luck.
--
I haven't checked it out carefully but I don't see any indication that Minecraft has stopped making the region files multiples of 4096? Do you have a reference?
What I see them saying is they have now fixed the bug which could cause problems if third party programs edited the region files without keeping to multiples of 4096, not that they had any plans to start using other lengths themselves.
Structure blocks can handle a maximum of 32x32x32 blocks. My house alone is bigger than that.
Well, here's what my region files look like now:
EDIT:
Oh wait, that's kilobytes, not bytes ... *does some calculation* Oh snap, they are all still multiples of 4096! Dang, I have no idea why it's deleting my chunks now. ><
The bugfix you mentioned has been around ever since the region file format was introduced in Beta 1.3 and only ever manifested itself when an external tool was used which didn't pad the file to a multiple of 4096, and all publicly available tools, like MCEdit, respected this (either intentionally or inadvertently):
(code from 1.6.4; the error is that they don't seek to the end of the file, instead it zeroes out the first 0-4095 bytes, which are used to store the location of chunks within the region file; worst-case this would reset every chunk. I noticed this myself a long time ago and fixed it just to be safe)
As for why chunks are reset, Mojang constantly changes the save format these days and newer versions are far less forgiving of unknown data - I wouldn't even trust downgrading by even a patch version (e.g. 1.14.4 to 1.14.3); the last time I'd trust this would be prior to 1.8 (I've tested opening a 1.6.4 world in 1.7.10, then going back and nothing happened; even opening a 1.7.10 world in 1.5.2 only resulting in the loss of unknown blocks and items; for example, a mesa biome turned into a stone wasteland; the biome in F3 was displayed as plains but the actual saved biome data wasn't changed as it returned when reopened in 1.7; likewise, opening a world generated in TMCW (modded 1.6.4) in vanilla causes the 1.8 stone types to appear as normal stone but their metadata is retained. Doing the same in 1.8+ would cause the game to freak out as it encounters invalid block states, which are actual objects, not just some numerical data, so you get fun things like NullPointerExceptions).
Great Scott, my stomach knotted seeing the word " NullPointerException." XD Thank you very much for the info! I once backdated a world from 1.10 to 1.7 and again, the only things I lost were new items; I was expecting this to happen again. I guess I'll just have to be more careful in the future!
Being at a loss of how to recover the snapshot world, I ended up loading up the 1.14.4 world and switching to creative mode to rebuild the stuff I did since the update. However, even though I can't backdate the region files, I /can/ backdate my inventory, so that certainly helps~
going back has never been supported. 19w36a changed the world format again. (3d biomes yay) you will not be able to downgrade any world from this version forward. similar changes happened in 1.14 and 1.13, you cant downgrade any of these versions.
So I loaded up a copy of my main survival world in the latest snapshot to play around with bees, but after that I forgot I was in the snapshot and did a load of work, so now I don't want to revert to the 1.14.4 backup. However, it would seem the following bugfix causes problems:
When I load up the world in 1.14.4, everything I've built gets erased because the chunks get regenerated. This is because the snapshot doesn't lock the region files to an exact multiple of 4096 bytes anymore. Does anyone have an idea of how to revert them back? I opened a region file with a hex editor, but unsurprisingly that wasn't much help. Would it be as simple as adding null characters until the file is an acceptable size? I don't know enough about the region file format.
You might be able to open the snapshot save in MC Edit, copy out the chunks you changed, then paste them into the save from 1.14.4, make backups of everything first, of course! It all depends on if MC Edit can read a snapshot save or not, I don't think it's been updated in a while, I haven't checked.
D_B
To tell them how to live is to prevent them living.
MCEdit is not compatible with versions past 1.12. A new similar program is in the works, but nobody knows when it'll be ready.
Have you verified that your region files aren't multiples of 4096?
I think that moving save files back to an earlier version always has caused problems, mostly because of new blocks that the older version doesn't recognize and therefore thinks the chunks are corrupted and regenerates them.
So I think you'll probably just have to continue in 1.15, though there's no real guarantee that the final release will be fully compatible with the snapshots.
--
You might be able to use the structure blocks to save your builds, after removing any new blocks like hives, and import them to 1.14 that way.
I wouldn't know, I've never looked at how the structure blocks work.
Be sure to make backups at every step!
Good luck.
--
I haven't checked it out carefully but I don't see any indication that Minecraft has stopped making the region files multiples of 4096? Do you have a reference?
What I see them saying is they have now fixed the bug which could cause problems if third party programs edited the region files without keeping to multiples of 4096, not that they had any plans to start using other lengths themselves.
Just testing.
Structure blocks can handle a maximum of 32x32x32 blocks. My house alone is bigger than that.
Well, here's what my region files look like now:
EDIT:
Oh wait, that's kilobytes, not bytes ... *does some calculation* Oh snap, they are all still multiples of 4096! Dang, I have no idea why it's deleting my chunks now. ><
The bugfix you mentioned has been around ever since the region file format was introduced in Beta 1.3 and only ever manifested itself when an external tool was used which didn't pad the file to a multiple of 4096, and all publicly available tools, like MCEdit, respected this (either intentionally or inadvertently):
(code from 1.6.4; the error is that they don't seek to the end of the file, instead it zeroes out the first 0-4095 bytes, which are used to store the location of chunks within the region file; worst-case this would reset every chunk. I noticed this myself a long time ago and fixed it just to be safe)
As for why chunks are reset, Mojang constantly changes the save format these days and newer versions are far less forgiving of unknown data - I wouldn't even trust downgrading by even a patch version (e.g. 1.14.4 to 1.14.3); the last time I'd trust this would be prior to 1.8 (I've tested opening a 1.6.4 world in 1.7.10, then going back and nothing happened; even opening a 1.7.10 world in 1.5.2 only resulting in the loss of unknown blocks and items; for example, a mesa biome turned into a stone wasteland; the biome in F3 was displayed as plains but the actual saved biome data wasn't changed as it returned when reopened in 1.7; likewise, opening a world generated in TMCW (modded 1.6.4) in vanilla causes the 1.8 stone types to appear as normal stone but their metadata is retained. Doing the same in 1.8+ would cause the game to freak out as it encounters invalid block states, which are actual objects, not just some numerical data, so you get fun things like NullPointerExceptions).
TheMasterCaver's First World - possibly the most caved-out world in Minecraft history - includes world download.
TheMasterCaver's World - my own version of Minecraft largely based on my views of how the game should have evolved since 1.6.4.
Why do I still play in 1.6.4?
Great Scott, my stomach knotted seeing the word " NullPointerException." XD Thank you very much for the info! I once backdated a world from 1.10 to 1.7 and again, the only things I lost were new items; I was expecting this to happen again. I guess I'll just have to be more careful in the future!
Being at a loss of how to recover the snapshot world, I ended up loading up the 1.14.4 world and switching to creative mode to rebuild the stuff I did since the update. However, even though I can't backdate the region files, I /can/ backdate my inventory, so that certainly helps~
going back has never been supported. 19w36a changed the world format again. (3d biomes yay) you will not be able to downgrade any world from this version forward. similar changes happened in 1.14 and 1.13, you cant downgrade any of these versions.
Ooohh, I remember reading about the 3D biomes thing! I didn't realize it had already been implemented. Thanks for the info! =3
It is implemented, but as of yet not used, still very curious what they will do with it