When trying to load worlds that were last used in Minecraft version 1.20 through 1.21.2

into the most recent version of Minecraft, 1.21.4, the world fails to load correctly and spams "Failed to load chunk at  [x,y]." And outputs a chunk error log into the debug folder.  In some cases, the entire world fails to load completely and you will fall into the void over and over. I have also noticed in some other scenarios, specifically with flatworld generation, chunks will get generated over and you will lose builds. 

I had my asset world that I use to make creations for my singleplayer RP world erased because of this, luckily I do make frequent backups so I didn't lose anything but the potential here is pretty bad when most people will continue to upgrade worlds from older versions. 

Worlds that are from earlier versions like 1.16-1.19 don't appear to have this problem but I have no extensively tried on them, only a handful and they load fine. 

Here is an example of the output log
"
---- Minecraft Chunk IO Error Report ----
// I have failed you!
 
Time: 2025-01-17 19:25:48
Description: Chunk load failure
 
java.lang.ArrayIndexOutOfBoundsException
 
 
A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------
 
– Head –
Thread: IO-Worker-6
Stacktrace:
at net.minecraft.server.MinecraftServer.a(SourceFile:2055)
 
– Chunk Info –
Details:
Level: world--
Dimension: minecraft:overworld
Storage: chunk
Position: [-193, -51]
Stacktrace:
at net.minecraft.server.MinecraftServer.a(SourceFile:2055)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.base/java.lang.Thread.run(Unknown Source)"