[MC-241790] Fatal (crash) error related with Biome decoration (IndexOutOfBoundsException)

Hello,

I've tested multiple worlds and all seem to have this very same issue. When the server tries to generate some chunks, it causes the following error:

java.util.concurrent.CompletionException: z: Biome decoration
        at java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:315) ~[?:?]
        at java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:320) ~[?:?]
        at java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:1159) ~[?:?]
        at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:482) ~[?:?]
        at acx.b(SourceFile:58) ~[server-1.18-pre3.jar:?]
        at auk.g(SourceFile:91) ~[server-1.18-pre3.jar:?]
        at auk.a(SourceFile:146) ~[server-1.18-pre3.jar:?]
        at auk.run(SourceFile:102) ~[server-1.18-pre3.jar:?]
        at java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1395) ~[?:?]
        at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:373) ~[?:?]
        at java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1182) ~[?:?]
        at java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1655) ~[?:?]
        at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1622) ~[?:?]
        at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:165) ~[?:?]
Caused by: z: Biome decoration
        at acv.a(SourceFile:639) ~[server-1.18-pre3.jar:?]
        at com.mojang.datafixers.util.Either$Left.map(Either.java:38) ~[datafixerupper-4.0.26.jar:?]
        at acv.a(SourceFile:621) ~[server-1.18-pre3.jar:?]
        at java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:1150) ~[?:?]
        ... 11 more
Caused by: java.lang.IndexOutOfBoundsException: Index 0 out of bounds for length 0
        at jdk.internal.util.Preconditions.outOfBounds(Preconditions.java:64) ~[?:?]
        at jdk.internal.util.Preconditions.outOfBoundsCheckIndex(Preconditions.java:70) ~[?:?]
        at jdk.internal.util.Preconditions.checkIndex(Preconditions.java:266) ~[?:?]
        at java.util.Objects.checkIndex(Objects.java:359) ~[?:?]
        at java.util.ArrayList.get(ArrayList.java:427) ~[?:?]
        at cpz.a(SourceFile:303) ~[server-1.18-pre3.jar:?]
        at cqb.c(SourceFile:146) ~[server-1.18-pre3.jar:?]
        at cqb.a(SourceFile:289) ~[server-1.18-pre3.jar:?]
        at acv.a(SourceFile:627) ~[server-1.18-pre3.jar:?]
        at com.mojang.datafixers.util.Either$Left.map(Either.java:38) ~[datafixerupper-4.0.26.jar:?]
        at acv.a(SourceFile:621) ~[server-1.18-pre3.jar:?]
        at java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:1150) ~[?:?]
        ... 11 more

The maps were generated on pre-1, then imported to pre-2. This error only happened on pre-3.

This happened on two worlds of mine so far. The worlds were generated when playing on multiplayer, but when imported locally into the saves folder, the problem it's still there.

What's even worse is, once that error shows up once, when joining the world again, the error is inmediatly generating again upon join (since its a generation-related error).

The exception makes the world/server crash.