Occasionally, chunks would not generate, commands would stop working, and the game would only close when force closed. This is the error message that it produced:

---- Minecraft Crash Report ----
// I feel sad now

Time: 6/15/18 2:07 PM
Description: Exception generating new chunk

java.util.concurrent.ExecutionException: java.lang.OutOfMemoryError: Java heap space
at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:2237)
at sm.c(SourceFile:126)
at bbj.d(SourceFile:248)
at bbj.l(SourceFile:243)
at bbj.a_(SourceFile:583)
at bbj.a(SourceFile:425)
at bbj.b(SourceFile:397)
at bbj.a(SourceFile:363)
at bbj.a(SourceFile:294)
at bbj.g(SourceFile:324)
at biw.a(SourceFile:51)
at boh.b(SourceFile:264)
at sn.n_(SourceFile:452)
at sn.i_(SourceFile:220)
at net.minecraft.server.MinecraftServer.w(SourceFile:693)
at net.minecraft.server.MinecraftServer.v(SourceFile:626)
at dir.v(SourceFile:156)
at net.minecraft.server.MinecraftServer.run(SourceFile:531)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.OutOfMemoryError: Java heap space
at it.unimi.dsi.fastutil.ints.IntArrayFIFOQueue.resize(IntArrayFIFOQueue.java:175)
at it.unimi.dsi.fastutil.ints.IntArrayFIFOQueue.expand(IntArrayFIFOQueue.java:189)
at it.unimi.dsi.fastutil.ints.IntArrayFIFOQueue.enqueue(IntArrayFIFOQueue.java:201)
at cbt.a(SourceFile:138)
at cbt.a(SourceFile:142)
at cbt.a(SourceFile:126)
at cbu.a(SourceFile:20)
at te.a(SourceFile:23)
at ta.a(SourceFile:35)
at bqi.a(SourceFile:95)
at th.a(SourceFile:61)
at th.a(SourceFile:24)
at agl$a.a(SourceFile:131)
at agl$a$$Lambda$1723/110348836.apply(Unknown Source)
at java.util.concurrent.CompletableFuture$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)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– Head –
Thread: Server thread
Stacktrace:
at sm.a(SourceFile:170)

– Chunk to be generated –
Details:
Location: -34406,40806
Position hash: 175264730413466
Generator: bsa@7c80c9bc
Stacktrace:
at sm.a(SourceFile:170)
at sm.c(SourceFile:129)
at bbj.d(SourceFile:248)
at bbj.l(SourceFile:243)
at bbj.a_(SourceFile:583)
at bbj.a(SourceFile:425)
at bbj.b(SourceFile:397)
at bbj.a(SourceFile:363)
at bbj.a(SourceFile:294)
at bbj.g(SourceFile:324)
at biw.a(SourceFile:51)
at boh.b(SourceFile:264)
at sn.n_(SourceFile:452)
at sn.i_(SourceFile:220)
at net.minecraft.server.MinecraftServer.w(SourceFile:693)
at net.minecraft.server.MinecraftServer.v(SourceFile:626)
at dir.v(SourceFile:156)
at net.minecraft.server.MinecraftServer.run(SourceFile:531)
at java.lang.Thread.run(Thread.java:745)

– Affected level –
Details:
Level name: thigwig
All players: 1 total; [sp['SailorDoge'/859, l='thigwig', x=-550713.61, y=77.88, z=652529.04]]
Chunk stats: ServerChunkCache: 2392 Drop: 0
Level seed: 1477581161
Level generator: ID 02 - largeBiomes, ver 0. Features enabled: true
Level generator options: null
Level spawn location: World: (-550605,69,649160), Chunk: (at 3,4,8 in -34413,40572; contains blocks -550608,0,649152 to -550593,255,649167), Region: (-1076,1267; contains chunks -34432,40544 to -34401,40575, blocks -550912,0,648704 to -550401,255,649215)
Level time: 12811029 game time, 1047 day time
Level dimension: 0
Level storage version: 0x04ABD - Anvil
Level weather: Rain time: 1 (now: false), thunder time: 1 (now: false)
Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true

– System Details –
Details:
Minecraft Version: 1.13-pre2
Operating System: Windows 10 (amd64) version 10.0
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 1275503624 bytes (1216 MB) / 3221225472 bytes (3072 MB) up to 3221225472 bytes (3072 MB)
JVM Flags: 9 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xss1M -Xmx3G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=16M
Profiler Position: N/A (disabled)
Player Count: 1 / 8; [sp['SailorDoge'/859, l='thigwig', x=-550713.61, y=77.88, z=652529.04]]
Data Packs: vanilla, file/Companion (incompatible)
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.