So I removed an item from my mod because it was just pretty pointless and when I tried loading a world I had made before removing it, instead of just erasing any trace of the item like every single time I've done something similar before 1.7, it refuses to load the world.

All I get is this crash report:

 

---- Minecraft Crash Report ----

// Don't be sad, have a hug! <3

 

Time: 5/21/14 12:15 PM

Description: Exception in server tick loop

 

cpw.mods.fml.common.registry.GameRegistryException: Failed to load the world - there are fatal block and item id issues

at cpw.mods.fml.common.FMLContainer.readData(FMLContainer.java:193)

at cpw.mods.fml.common.FMLCommonHandler.handleWorldDataLoad(FMLCommonHandler.java:386)

at net.minecraft.world.storage.SaveHandler.func_75757_d(SaveHandler.java:142)

at net.minecraft.server.MinecraftServer.func_71247_a(MinecraftServer.java:344)

at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:292)

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:622)

at java.lang.Thread.run(Unknown Source)

 

 

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

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

 

-- System Details --

Details:

Minecraft Version: 1.7.2

Operating System: Windows 8 (amd64) version 6.2

Java Version: 1.7.0_51, Oracle Corporation

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

Memory: 700030024 bytes (667 MB) / 915406848 bytes (873 MB) up to 955252736 bytes (911 MB)

JVM Flags: 2 total; -Xmx1024M -Xms1024M

AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used

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

FML: MCP v9.01-pre FML v7.2.116.36 Minecraft Forge 10.12.0.1047 17 mods loaded, 17 mods active

mcp{8.09} [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

FML{7.2.116.36} [Forge Mod Loader] (mcpc-plus-1.7.2-R0.4-forge1047-B53.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

Forge{10.12.0.1047} [Minecraft Forge] (mcpc-plus-1.7.2-R0.4-forge1047-B53.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

grim3212core{V0.1 - 1.7.2} [Grim3212 Core] (Grim3212 Core-V0.1 - 1.7.2.jar.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

grim3212backpacks{V0.1 - 1.7.2} [Grim3212 Backpacks] (Backpacks-V0.1 - 1.7.2.jar.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

BiblioCraft{1.6.3} [biblioCraft] (BiblioCraft[1.6.3][MC1.7.2].jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

customnpcs{1.7.2-2} [CustomNpcs] (CustomNPCs-1.7.2-test.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

ForgeMultipart{G1.0.1-mc1.7.2} [Forge Multipart] (ForgeMultipart-G1.0.1-mc1.7.2.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

McMultipart{G1.0.1-mc1.7.2} [Minecraft Multipart Plugin] (ForgeMultipart-G1.0.1-mc1.7.2.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

pixelmoncore{0.1 MC1.7.2} [pixelmoncore] (PixelmonCore-1.6.4.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

ProjRed|Core{G1.0.1-mc1.7.2} [ProjectRed] (ProjectRed-G1.0.2-mc1.7.2.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

ProjRed|Exploration{G1.0.1-mc1.7.2} [ProjectRed-Exploration] (ProjectRed-G1.0.2-mc1.7.2.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

ProjRed|Illumination{G1.0.1-mc1.7.2} [ProjectRed-Illumination] (ProjectRed-G1.0.2-mc1.7.2.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

ProjRed|Integration{G1.0.1-mc1.7.2} [ProjectRed-Integration] (ProjectRed-G1.0.2-mc1.7.2.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

ProjRed|Transmission{G1.0.1-mc1.7.2} [ProjectRed-Transmission] (ProjectRed-G1.0.2-mc1.7.2.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

TwilightForest{2.0.3} [The Twilight Forest] (twilightforest-1.7.2-2.0.3.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

ForgeMicroblock{G1.0.1-mc1.7.2} [Forge Microblocks] (ForgeMultipart-G1.0.1-mc1.7.2.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available

Profiler Position: N/A (disabled)

Player Count: 0 / 20; []

Is Modded: Definitely; Server brand changed to 'mcpc,craftbukkit,fml,forge'

Type: Dedicated Server (map_server.txt)

 

 

Anyone know what's going on or how to fix it?

How are you starting minecraft?

Try handling the FMLMissingMappingsEvent event.

the id didn´t got removed from nbt tag. use a nbt editor and remove the item from world

Update forge. It's that simple. Use at least recommended (1060)