Game crashes after sighting an iceberg

When exploring the area around my starting position with a donkey, i sighted an iceberg near the coast. When I tried to get nearer, the game crashed (see below). It's impossible to play the game now, because it crashes immediately after loading. Is there a way to repair the save file ?
World seed: 6948802166969341737

---- Minecraft Crash Report ----
// I'm sorry, Dave.

Time: 05.05.18 15:35
Description: Exception generating new chunk

java.util.concurrent.ExecutionException: java.lang.RuntimeException: We are asking a region for a chunk out of bound | 55 161
	at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:2237)
	at sg.c(SourceFile:129)
	at auv.c(SourceFile:246)
	at auv.p(SourceFile:242)
	at auv.b(SourceFile:591)
	at avg.a(SourceFile:218)
	at avg.a(SourceFile:145)
	at sh.k_(SourceFile:195)
	at net.minecraft.server.MinecraftServer.w(SourceFile:696)
	at net.minecraft.server.MinecraftServer.v(SourceFile:629)
	at dbc.v(SourceFile:156)
	at net.minecraft.server.MinecraftServer.run(SourceFile:534)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.RuntimeException: We are asking a region for a chunk out of bound | 55 161
	at sm.c(SourceFile:118)
	at sm.a(SourceFile:104)
	at sm.b(SourceFile:124)
	at sm.c(SourceFile:129)
	at brx.a(SourceFile:88)
	at bsb.a(SourceFile:139)
	at bsb.a(SourceFile:117)
	at bsb.a(SourceFile:62)
	at bsb.a(SourceFile:19)
	at bsc.a(SourceFile:27)
	at biy.a(SourceFile:64)
	at st.a(SourceFile:13)
	at su.a(SourceFile:33)
	at bjc.a(SourceFile:85)
	at ta.a(SourceFile:54)
	at ta.a(SourceFile:23)
	at zy$a.a(SourceFile:143)
	at zy$a$$Lambda$1030/1920074842.apply(Unknown Source)
	at java.util.concurrent.CompletableFuture$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 sg.a(SourceFile:178)

-- Chunk to be generated --
Details:
	Location: 55,161
	Position hash: 691489734711
	Generator: bks@404f9842
Stacktrace:
	at sg.a(SourceFile:178)
	at sg.c(SourceFile:132)
	at auv.c(SourceFile:246)
	at auv.p(SourceFile:242)
	at auv.b(SourceFile:591)
	at avg.a(SourceFile:218)
	at avg.a(SourceFile:145)
	at sh.k_(SourceFile:195)
	at net.minecraft.server.MinecraftServer.w(SourceFile:696)
	at net.minecraft.server.MinecraftServer.v(SourceFile:629)
	at dbc.v(SourceFile:156)
	at net.minecraft.server.MinecraftServer.run(SourceFile:534)
	at java.lang.Thread.run(Thread.java:745)

-- Affected level --
Details:
	Level name: Test1
	All players: 1 total; [sj['Nopse'/392, l='Test1', x=837,08, y=68,60, z=2654,80]]
	Chunk stats: ServerChunkCache: 1107 Drop: 0
	Level seed: 6948802166969341737
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: {}
	Level spawn location: World: (-107,64,5), Chunk: (at 5,4,5 in -7,0; contains blocks -112,0,0 to -97,255,15), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 5760548 game time, 10354721 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 145460 (now: false), thunder time: 26956 (now: false)
	Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false

-- System Details --
Details:
	Minecraft Version: 18w16a
	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: 560541144 bytes (534 MB) / 889192448 bytes (848 MB) up to 2147483648 bytes (2048 MB)
	JVM Flags: 8 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx2G -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; [sj['Nopse'/392, l='Test1', x=837,08, y=68,60, z=2654,80]]
	Data Packs: vanilla
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.