Game freezes without crash logs when upgrading from 1.12.2 to 1.18 pre-5

The bug is related to the change in the height of the world?

I was able to open the world on MacOS Monterey 12.0.1. on the pre-relaese (5)

There are 2 blocks at former build height (close to where I spawned) and normal terrain below around y70. Is that how it is supposed to be?

Make your render distance 32

Indeed, that makes the gamewindow go black after a while... I see. 

It gave me this in the log in the launcher upon freezing up: 

Encountered an unexpected exception java.util.concurrent.CompletionException: z: Feature placement at java.base/java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:315) at java.base/java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:320) at java.base/java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:1159) at java.base/java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:482) at acx.b(SourceFile:58) at auk.g(SourceFile:91) at auk.a(SourceFile:146) at auk.run(SourceFile:102) at java.base/java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1395) at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:373) at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1182) at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1655) at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1622) at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:165) Caused by: z: Feature placement at acv.a(SourceFile:639) at com.mojang.datafixers.util.Either$Left.map(Either.java:38) at acv.a(SourceFile:621) at java.base/java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:1150) ... 11 more Caused by: java.lang.IllegalArgumentException: Cannot set property cou{name=extended, clazz=class java.lang.Boolean, values=[true, false]} as it does not exist in Block{minecraft:air} at coe.a(SourceFile:117) at cny.a(SourceFile:364) at cnu.c(SourceFile:115) at cob$a.b(SourceFile:839) at cob$a.k(SourceFile:835) at cjk.a(SourceFile:96) at cob$a.a(SourceFile:969) at caz.b(SourceFile:310) at cye.a(SourceFile:41) at cvv.a(SourceFile:80) at ddw.a(SourceFile:56) at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183) at java.base/java.util.stream.Streams$StreamBuilderImpl.forEachRemaining(Streams.java:411) at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:762) at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:276) at java.base/java.util.stream.Streams$StreamBuilderImpl.forEachRemaining(Streams.java:411) at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150) at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173) at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596) at ddw.a(SourceFile:55) at ddw.b(SourceFile:44) at cpz.a(SourceFile:315) at cqb.c(SourceFile:146) at cqb.a(SourceFile:289) at acv.a(SourceFile:627) ... 14 more

And upon killing the java process I get the attached crash report. ("
The game crashed whilst exception in server tick loop
Error: java.util.concurrent.CompletionException: z: Feature placement
Exit Code: 9
")

This stack trace is MC-241956, so not sure if it's really related to the world save file.

Edit: Inspected the deobfuscated stack trace closer and it's not quite the same issue, so... marking as related I guess