Can't open world from 1.12

After trying opening world in newest snapshot like 18w20c or 18w21a i'm stuck on Loading area screen with Preparing spawn area 0% spam on logs. Attaching world that can be opened in 1.12.2, but can't in new snaps:

^{Found while testing: MC-125038}

Description: Exception in server tick loop

java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.util.ConcurrentModificationException
	at net.minecraft.server.MinecraftServer.g_(SourceFile:392)
	at dik.a(SourceFile:116)
	at dik.d(SourceFile:132)
	at net.minecraft.server.MinecraftServer.run(SourceFile:501)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.util.concurrent.ExecutionException: java.util.ConcurrentModificationException
	at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:2272)
	at net.minecraft.server.MinecraftServer.g_(SourceFile:390)
	... 4 more
Caused by: java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901)
	at java.util.ArrayList$Itr.next(ArrayList.java:851)
	at bzx.b(SourceFile:178)
	at bzx.c(SourceFile:214)
	at bzx.a(SourceFile:34)
	at bzx$p.c(SourceFile:352)
	at bzx$d.a(SourceFile:835)
	at bwj$a.<init>(SourceFile:89)
	at bwj.a(SourceFile:61)
	at bwk.a(SourceFile:233)
	at bwk.a(SourceFile:71)
	at byq.a(SourceFile:16)
	at byq.a(SourceFile:13)
	at bsn.a(SourceFile:27)
	at bca.a(SourceFile:515)
	at bqa.a(SourceFile:109)
	at ta.a(SourceFile:12)
	at sz.a(SourceFile:34)
	at bqe.a(SourceFile:95)
	at tg.a(SourceFile:62)
	at tg.a(SourceFile:25)
	at agi$a.a(SourceFile:131)
	at agi$a$$Lambda$1566/401714752.apply(Unknown Source)
	at java.util.concurrent.CompletableFuture$AsyncApply.exec(CompletableFuture.java:501)
	at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
	at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:902)
	at java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1689)
	at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1644)
	at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)