this is what comes out before the stop message
[13:12:47] [Server thread/WARN]: Could not set level chunk heightmap, array length is 0 instead of 256
174[13:12:47] [Server thread/WARN]: Could not set level chunk heightmap, array length is 0 instead of 256
175[13:12:47] [Server thread/WARN]: Could not set level chunk heightmap, array length is 0 instead of 256
176[13:12:47] [Server thread/ERROR]: Encountered an unexpected exception
177java.lang.IllegalArgumentException: ChunkNibbleArrays should be 2048 bytes not: 0
178 at net.minecraft.server.v1_12_R1.NibbleArray.<init>(NibbleArray.java:14) ~[minecraft_server.jar:git-Spigot-eb3d921-2b93d83]
179 at net.minecraft.server.v1_12_R1.ChunkRegionLoader.a(ChunkRegionLoader.java:402) ~[minecraft_server.jar:git-Spigot-eb3d921-2b93d83]
180 at net.minecraft.server.v1_12_R1.ChunkRegionLoader.a(ChunkRegionLoader.java:94) ~[minecraft_server.jar:git-Spigot-eb3d921-2b93d83]
181 at net.minecraft.server.v1_12_R1.ChunkRegionLoader.loadChunk(ChunkRegionLoader.java:72) ~[minecraft_server.jar:git-Spigot-eb3d921-2b93d83]
182 at org.bukkit.craftbukkit.v1_12_R1.chunkio.ChunkIOProvider.callStage1(ChunkIOProvider.java:21) ~[minecraft_server.jar:git-Spigot-eb3d921-2b93d83]
183 at org.bukkit.craftbukkit.v1_12_R1.chunkio.ChunkIOProvider.callStage1(ChunkIOProvider.java:1) ~[minecraft_server.jar:git-Spigot-eb3d921-2b93d83]
184 at org.bukkit.craftbukkit.v1_12_R1.util.AsynchronousExecutor.skipQueue(AsynchronousExecutor.java:336) ~[minecraft_server.jar:git-Spigot-eb3d921-2b93d83]
185 at org.bukkit.craftbukkit.v1_12_R1.util.AsynchronousExecutor.getSkipQueue(AsynchronousExecutor.java:295) ~[minecraft_server.jar:git-Spigot-eb3d921-2b93d83]
186 at org.bukkit.craftbukkit.v1_12_R1.chunkio.ChunkIOExecutor.syncChunkLoad(ChunkIOExecutor.java:16) ~[minecraft_server.jar:git-Spigot-eb3d921-2b93d83]
187 at net.minecraft.server.v1_12_R1.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:137) ~[minecraft_server.jar:git-Spigot-eb3d921-2b93d83]
188 at net.minecraft.server.v1_12_R1.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:120) ~[minecraft_server.jar:git-Spigot-eb3d921-2b93d83]
189 at net.minecraft.server.v1_12_R1.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:116) ~[minecraft_server.jar:git-Spigot-eb3d921-2b93d83]
190 at net.minecraft.server.v1_12_R1.MinecraftServer.l(MinecraftServer.java:374) ~[minecraft_server.jar:git-Spigot-eb3d921-2b93d83]
191 at net.minecraft.server.v1_12_R1.MinecraftServer.a(MinecraftServer.java:338) ~[minecraft_server.jar:git-Spigot-eb3d921-2b93d83]
192 at net.minecraft.server.v1_12_R1.DedicatedServer.init(DedicatedServer.java:272) ~[minecraft_server.jar:git-Spigot-eb3d921-2b93d83]
193 at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:545) [minecraft_server.jar:git-Spigot-eb3d921-2b93d83]
194 at java.lang.Thread.run(Thread.java:748) [?:1.8.0_144]
195[13:12:47] [Server thread/ERROR]: This crash report has been saved to: /aternos/server/./crash-reports/crash-2018-08-13_13.12.47-server.txt