Minecraft freezes on world loading screen

When I try to test my mod I go into Minecraft but it freezes on the world loading screen and says Minecraft has run  out of memory. This only happens with this mod( I have a world with 30 mods on it). And it doesn't happen with no mods. Here is the error report and if there is anything else you would need to see just tell me. Thanks.

---- Minecraft Crash Report ----

// Oops.

Time: 1/20/14 8:48 PM

Description: Ticking entity

java.lang.OutOfMemoryError: Java heap space

at net.minecraft.network.packet.Packet51MapChunk.getMapChunkData(Packet51MapChunk.java:276)

at net.minecraft.network.packet.Packet56MapChunks.<init>(Packet56MapChunks.java:55)

at net.minecraft.entity.player.EntityPlayerMP.onUpdate(EntityPlayerMP.java:298)

at net.minecraft.world.World.updateEntityWithOptionalForce(World.java:2350)

at net.minecraft.world.WorldServer.updateEntityWithOptionalForce(WorldServer.java:719)

at net.minecraft.world.World.updateEntity(World.java:2311)

at net.minecraft.world.World.updateEntities(World.java:2157)

at net.minecraft.world.WorldServer.updateEntities(WorldServer.java:550)

at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:668)

at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:587)

at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:129)

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:484)

at net.minecraft.server.ThreadMinecraftServer.run(ThreadMinecraftServer.java:583)

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

---------------------------------------------------------------------------------------

-- Head --

Stacktrace:

at net.minecraft.network.packet.Packet51MapChunk.getMapChunkData(Packet51MapChunk.java:276)

at net.minecraft.network.packet.Packet56MapChunks.<init>(Packet56MapChunks.java:55)

at net.minecraft.entity.player.EntityPlayerMP.onUpdate(EntityPlayerMP.java:298)

at net.minecraft.world.World.updateEntityWithOptionalForce(World.java:2350)

at net.minecraft.world.WorldServer.updateEntityWithOptionalForce(WorldServer.java:719)

at net.minecraft.world.World.updateEntity(World.java:2311)

-- Entity being ticked --

Details:

Entity Type: null (net.minecraft.entity.player.EntityPlayerMP)

Entity ID: 13

Entity Name: Player74

Entity's Exact location: 205.50, 56.00, 247.50

Entity's Block location: World: (205,56,247), Chunk: (at 13,3,7 in 12,15; contains blocks 192,0,240 to 207,255,255), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)

Entity's Momentum: 0.00, 0.00, 0.00

Stacktrace:

at net.minecraft.world.World.updateEntities(World.java:2157)

at net.minecraft.world.WorldServer.updateEntities(WorldServer.java:550)

-- Affected level --

Details:

Level name: New World

All players: 1 total; [EntityPlayerMP['Player74'/13, l='New World', x=205.50, y=56.00, z=247.50]]

Chunk stats: ServerChunkCache: 625 Drop: 0

Level seed: -8957444029408463989

Level generator: ID 00 - default, ver 1. Features enabled: true

Level generator options:

Level spawn location: World: (196,64,244), Chunk: (at 4,4,4 in 12,15; contains blocks 192,0,240 to 207,255,255), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)

Level time: 135 game time, 135 day time

Level dimension: 0

Level storage version: 0x04ABD - Anvil

Level weather: Rain time: 66239 (now: false), thunder time: 102905 (now: false)

Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true

Stacktrace:

at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:668)

at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:587)

at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:129)

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:484)

at net.minecraft.server.ThreadMinecraftServer.run(ThreadMinecraftServer.java:583)

-- System Details --

Details:

Minecraft Version: 1.6.4

Operating System: Windows 8 (amd64) version 6.2

Java Version: 1.7.0_45, Oracle Corporation

Java VM Version: Java HotSpot 64-Bit Server VM (mixed mode), Oracle Corporation

Memory: 124592 bytes (0 MB) / 1056309248 bytes (1007 MB) up to 1056309248 bytes (1007 MB)

JVM Flags: 3 total; -Xincgc -Xmx1024M -Xms1024M

AABB Pool Size: 2989 (167384 bytes; 0 MB) allocated, 58 (3248 bytes; 0 MB) used

Suspicious classes: FML and Forge are installed

IntCache: cache: 0, tcache: 0, allocated: 3, tallocated: 63

FML: ~~ERROR~~ OutOfMemoryError: Java heap space

Profiler Position: N/A (disabled)

Vec3 Pool Size: 6089 (340984 bytes; 0 MB) allocated, 32 (1792 bytes; 0 MB) used

Player Count: 1 / 8; [EntityPlayerMP['Player74'/13, l='New World', x=205.50, y=56.00, z=247.50]]

Type: Integrated Server (map_client.txt)

Is Modded: Definitely; Client brand changed to 'fml,forge'

Hi

Does it happen when just your mod is installed and not any others?  It looks like your mod might be using up a lot of heap space and there is none left for vanilla stuff.

You might be able to get a clue using a heap analyser

eg

http://stackoverflow.com/questions/145922/how-can-i-see-what-is-in-my-heap-in-java

http://blog.jeroenreijn.com/2010/10/large-heap-dump-analysis-with-eclipse.html

-TGG

All I added in my mod is an item, fuel handler, an ore, and the ore's world generation. How does that use up less than some mods I use like Tinker's Construct, Mekanism, and Buildcraft.? And how would I fix this?

Hi

Yeah your mod shouldn't need a large amount of memory if that's all it's doing.  I suspect that you've implemented something not quite right (probably the world generation?).  Hard to tell what.  That's why I suggested the heap analyser - if you look at the heap after the crash, and discover that it's nearly completely full of a particular object (say - 1,0000,000 copies of your Item), then you have a strong clue where the problem is.

If you're not keen on the heap analyser idea, I would suggest you try and narrow down the part of the code which is causing the problem by commenting some of it out, running to see if it crashes, uncomment (or comment more), etc, until you can put your finger on the exact part of the code which leads to the crash.

Memory problems can be tricky to fix, it might take a fair bit of trial & error (and patience).

If you really get stumped, you could consider posting your code (say, on GitHub), and some eager person on this forum might try to reproduce+troubleshoot the error for you :-)

-TGG

Fixed it. Thanks for the help!