I was playing on 1.8.9 the other day and had accidentally clicked on a world created in 1.16.5, but had a different and unique seed that I can’t remember. After exiting the game I returned to 1.16.5 and found my world corrupted, as in my flat building world was now in-flat and had a seed of 0.
Is there a way to restore or find the seed that was lost? I might also need help recovering my world, since some methods require knowing the seed.
I don’t have the world backed up, which I know is my fault, but is there a way to recover it or is it lost forever?
Unless you made a backup or Windows made one (try right-clicking on the save folder and check "restore previous versions", but this is not enabled by default) there is nothing that can be done; the save format that 1.16 uses is completely different from 1.8 - it isn't just that 1.16 has blocks, items, and entities that 1.8 doesn't recognize and which will always be lost if you downgrade, but the very way data is stored is completely different, so the game simply regenerated everything from scratch. Even downgrading by a single version, especially if it is newer than 1.13, can completely ruin a world (newer versions rely on knowing the "data version" in order to read save data, which can be no newer than the current version).
It may also be possible to recover the seed from "level.dat_old" with a tool like NBTExplorer, in the chance that the game did not update it (though since you loaded the world at least twice it probably was since it is a backup of level.dat from the last save, which happens every time you save and quit). if you ever used the /seed command you can also find it in the game logs (.minecraft\logs, with each session in a separate zipped file).
Also, to help minimize the risk of this happening again, always run separate versions in separate game directories. You should also be making regular backups for many other reasons other than cases like this.
I was playing on 1.8.9 the other day and had accidentally clicked on a world created in 1.16.5, but had a different and unique seed that I can’t remember. After exiting the game I returned to 1.16.5 and found my world corrupted, as in my flat building world was now in-flat and had a seed of 0.
Is there a way to restore or find the seed that was lost? I might also need help recovering my world, since some methods require knowing the seed.
I don’t have the world backed up, which I know is my fault, but is there a way to recover it or is it lost forever?
Thanks, also my weird username is a placeholder.
See https://www.minecraftforum.net/forums/minecraft-java-edition/discussion/297844-official-corrupted-save-recovery-thread
Unless you made a backup or Windows made one (try right-clicking on the save folder and check "restore previous versions", but this is not enabled by default) there is nothing that can be done; the save format that 1.16 uses is completely different from 1.8 - it isn't just that 1.16 has blocks, items, and entities that 1.8 doesn't recognize and which will always be lost if you downgrade, but the very way data is stored is completely different, so the game simply regenerated everything from scratch. Even downgrading by a single version, especially if it is newer than 1.13, can completely ruin a world (newer versions rely on knowing the "data version" in order to read save data, which can be no newer than the current version).
It may also be possible to recover the seed from "level.dat_old" with a tool like NBTExplorer, in the chance that the game did not update it (though since you loaded the world at least twice it probably was since it is a backup of level.dat from the last save, which happens every time you save and quit). if you ever used the /seed command you can also find it in the game logs (.minecraft\logs, with each session in a separate zipped file).
Also, to help minimize the risk of this happening again, always run separate versions in separate game directories. You should also be making regular backups for many other reasons other than cases like this.
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?