Exception generating new chunk

 [12:12:53] [WorldGen-Scheduler-1/ERROR]: Couldn't load structure minecraft:ruin/big_brick_8: java.io.FileNotFoundException: minecraft:structures/ruin/big_brick_8.nbt
[12:12:53] [WorldGen-Scheduler-1/ERROR]: Couldn't load structure minecraft:ruin/big_cracked_8: java.io.FileNotFoundException: minecraft:structures/ruin/big_cracked_8.nbt
[12:12:53] [WorldGen-Scheduler-1/ERROR]: Couldn't load structure minecraft:ruin/big_mossy_8: java.io.FileNotFoundException: minecraft:structures/ruin/big_mossy_8.nbt
[12:12:56] [Server thread/ERROR]: Encountered an unexpected exception
h: Exception generating new chunk
 at net.minecraft.server.MinecraftServer.w(SourceFile:693) ~[server.jar:?]
 at ru.w(SourceFile:365) ~[server.jar:?]
 at net.minecraft.server.MinecraftServer.v(SourceFile:622) ~[server.jar:?]
 at net.minecraft.server.MinecraftServer.run(SourceFile:527) [server.jar:?]
 at java.lang.Thread.run(Thread.java:748) [?:1.8.0_171]
Caused by: java.util.concurrent.ExecutionException: java.lang.IllegalArgumentException: bound must be positive
 at java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:357) ~[?:1.8.0_171]
 at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1895) ~[?:1.8.0_171]
 at si.c(SourceFile:130) ~[server.jar:?]
 at sq.a(SourceFile:84) ~[server.jar:?]
 at sr.c(SourceFile:143) ~[server.jar:?]
 at sj.i_(SourceFile:223) ~[server.jar:?]
 at net.minecraft.server.MinecraftServer.w(SourceFile:689) ~[server.jar:?]
 ... 4 more

---- Minecraft Crash Report ----
 // Oh - I know what I did wrong!
Time: 5/16/18 12:12 PM
 Description: Exception generating new chunk
java.util.concurrent.ExecutionException: java.lang.IllegalArgumentException: bound must be positive
 at java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:357)
 at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1895)
 at si.c(SourceFile:130)
 at sq.a(SourceFile:84)
 at sr.c(SourceFile:143)
 at sj.i_(SourceFile:223)
 at net.minecraft.server.MinecraftServer.w(SourceFile:689)
 at ru.w(SourceFile:365)
 at net.minecraft.server.MinecraftServer.v(SourceFile:622)
 at net.minecraft.server.MinecraftServer.run(SourceFile:527)
 at java.lang.Thread.run(Thread.java:748)
 Caused by: java.lang.IllegalArgumentException: bound must be positive
 at java.util.Random.nextInt(Random.java:388)
 at bzs.a(SourceFile:203)
 at bzu.a(SourceFile:186)
 at bzu.a(SourceFile:182)
 at bzj.a(SourceFile:59)
 at byz$a.a(SourceFile:266)
 at bzh.a(SourceFile:60)
 at bvq.a(SourceFile:90)
 at bxw.a(SourceFile:16)
 at bxw.a(SourceFile:13)
 at brt.a(SourceFile:27)
 at bbv.a(SourceFile:515)
 at bpg.a(SourceFile:109)
 at sx.a(SourceFile:12)
 at sw.a(SourceFile:33)
 at bpk.a(SourceFile:85)
 at tc.a(SourceFile:59)
 at tc.a(SourceFile:23)
 at agd$a.a(SourceFile:143)
 at java.util.concurrent.CompletableFuture.uniApply(CompletableFuture.java:602)
 at java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:577)
 at java.util.concurrent.CompletableFuture$Completion.exec(CompletableFuture.java:443)
 at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
 at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
 at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
 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 java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:357)
– Chunk to be generated –
 Details:
 Location: 20,-16
 Position hash: -68719476716
 Generator: brb@41be68d7
 Stacktrace:
 at si.a(SourceFile:180)
 at si.c(SourceFile:133)
 at sq.a(SourceFile:84)
 at sr.c(SourceFile:143)
 at sj.i_(SourceFile:223)
 at net.minecraft.server.MinecraftServer.w(SourceFile:689)
 at ru.w(SourceFile:365)
 at net.minecraft.server.MinecraftServer.v(SourceFile:622)
 at net.minecraft.server.MinecraftServer.run(SourceFile:527)
 at java.lang.Thread.run(Thread.java:748)
– Affected level –
 Details:
 Level name: nocturne
 All players: 1 total; [sl['Arcanjo77PT'/52, l='nocturne', x=334.65, y=69.00, z=-416.85]]
 Chunk stats: ServerChunkCache: 1148 Drop: 0
 Level seed: 150518150518150518
 Level generator: ID 00 - default, ver 1. Features enabled: true
 Level generator options: {}
 Level spawn location: World: (0,66,0), Chunk: (at 0,4,0 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
 Level time: 1056040 game time, 1067101 day time
 Level dimension: 0
 Level storage version: 0x04ABD - Anvil
 Level weather: Rain time: 9410 (now: false), thunder time: 25098 (now: false)
 Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
– System Details –
 Details:
 Minecraft Version: 18w20a
 Operating System: Linux (amd64) version 4.4.0-124-generic
 Java Version: 1.8.0_171, Oracle Corporation
 Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Oracle Corporation
 Memory: 1046380536 bytes (997 MB) / 1920466944 bytes (1831 MB) up to 2863661056 bytes (2731 MB)
 JVM Flags: 2 total; -Xms1G -Xmx3G
 Profiler Position: N/A (disabled)
 Player Count: 1 / 8; [sl['Arcanjo77PT'/52, l='nocturne', x=334.65, y=69.00, z=-416.85]]
 Data Packs: vanilla
 Is Modded: Unknown (can't tell)
 Type: Dedicated Server (map_server.txt)