Crash Report

java.lang.OutOfMemoryError: Java heap space
    at java.util.HashMap.newNode(HashMap.java:1734)
    at java.util.HashMap.putVal(HashMap.java:630)
    at java.util.HashMap.put(HashMap.java:611)
    at net.minecraft.server.v1_8_R3.NBTTagCompound.set(SourceFile:87)
    at net.minecraft.server.v1_8_R3.NBTTagCompound.clone(SourceFile:364)
    at net.minecraft.server.v1_8_R3.NBTTagList.clone(NBTTagList.java:186)
    at net.minecraft.server.v1_8_R3.NBTTagCompound.clone(SourceFile:364)
    at net.minecraft.server.v1_8_R3.NBTTagCompound.clone(SourceFile:364)
    at net.minecraft.server.v1_8_R3.NBTTagCompound.clone(SourceFile:364)
    at net.minecraft.server.v1_8_R3.NBTTagList.clone(NBTTagList.java:186)
    at net.minecraft.server.v1_8_R3.NBTTagCompound.clone(SourceFile:364)
    at net.minecraft.server.v1_8_R3.NBTTagCompound.clone(SourceFile:364)
    at net.minecraft.server.v1_8_R3.ItemStack.c(ItemStack.java:273)
    at net.minecraft.server.v1_8_R3.ItemStack.createStack(ItemStack.java:76)
    at net.minecraft.server.v1_8_R3.TileEntityChest.a(TileEntityChest.java:130)
    at net.minecraft.server.v1_8_R3.TileEntity.c(TileEntity.java:81)
    at net.minecraft.server.v1_8_R3.ChunkRegionLoader.loadEntities(ChunkRegionLoader.java:430)
    at org.bukkit.craftbukkit.v1_8_R3.chunkio.ChunkIOProvider.callStage2(ChunkIOProvider.java:46)
    at org.bukkit.craftbukkit.v1_8_R3.chunkio.ChunkIOProvider.callStage2(ChunkIOProvider.java:1)
    at org.bukkit.craftbukkit.v1_8_R3.util.AsynchronousExecutor$Task.finish(AsynchronousExecutor.java:188)
    at org.bukkit.craftbukkit.v1_8_R3.util.AsynchronousExecutor.finishActive(AsynchronousExecutor.java:347)
    at org.bukkit.craftbukkit.v1_8_R3.chunkio.ChunkIOExecutor.tick(ChunkIOExecutor.java:34)
    at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:734)
    at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:374)
    at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:654)
    at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:557)
    at java.lang.Thread.run(Thread.java:745)