MC-161823Chunks can occasionally be misplaced upon loading a world
If you have encountered this issue and your world is broken, you need to restore it from a backup, if you have one.
If you do not have a backup, you will need to repair the world manually. You can do that with mcaselector for example, a tool for managing and deleting chunks in a Minecraft world. It is also capable of swapping chunks, which you can use in order to fix worlds that have been corrupted by this bug. Please note that this tool is not supported by Mojang or the moderator team in any way.
We recommend making a backup of your world before trying to repair it manually, in case things go wrong even more.
The bug
Despite MC-150202 being marked as fixed, sometimes chunks still seem to be corrupted in the 1.15 snapshots. More details can be found in the attachments, as well as in the duplicates of this ticket.
Original description
I don't know how this happened but when i joined my world all the chunks were jumbled up, thankfully i have a backup but still this shouldnt happen.
