Server crash on generating world

I'm running a local MC server, and it will repeatedly crash when trying to generate a world. It seems to generate a little bit more each time the server is relaunched, before crashing again soon after. The only way for the server to generate worlds is if I relaunch it over and over until it finally finishes.

1.13.2: [^crash-2018-11-11_15.40.19-server.txt]

Description: Writing into PalettedContainer from multiple threads

java.lang.IllegalStateException
	at bnq.b(SourceFile:43)
	at bnq.a(SourceFile:110)
	at bnk.a(SourceFile:68)
	at bnr.a(SourceFile:168)
	at ti.a(SourceFile:217)
	at bpa.b(SourceFile:59)
	at bpa.a(SourceFile:45)
	at btt.a(SourceFile:98)
	at bpa.a(SourceFile:66)
	at bsp.a(SourceFile:23)
	at bsp.a(SourceFile:18)
	at bsp.a(SourceFile:10)
	at buu.a(SourceFile:24)
	at buu.a(SourceFile:13)
	at bpn.a(SourceFile:27)
	at ayu.a(SourceFile:504)
	at bmz.a(SourceFile:113)
	at tr.a(SourceFile:12)
	at tq.a(SourceFile:35)
	at bnd.a(SourceFile:95)
	at tx.a(SourceFile:79)
	at tx.a(SourceFile:25)
	at acu$a.a(SourceFile:147)
	at acu$a$$Lambda$1469/484300965.apply(Unknown Source)
	at java.util.concurrent.CompletableFuture$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)