I have made sure to install Forge, Optifine, and any other mods on the host server. The game works in singleplayer just fine. I updated the video card drivers for the computer that crashes and also Java. Here is the error report:
Minecraft has crashed!
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Minecraft has stopped running because it encountered a problem; Unexpected error
This error has been saved to C:\Documents and Settings\Deanna\Application Data\.minecraft\crash-reports\crash-2012-09-29_08.53.10-client.txt for your convenience. Please include a copy of this file if you report this crash to anyone.
--- BEGIN ERROR REPORT 9b31543 --------
Generated 9/29/12 8:53 AM
- Minecraft Version: 1.3.2
- Operating System: Windows XP (x86) version 5.1
- Java Version: 1.7.0_07, Oracle Corporation
- Java VM Version: Java HotSpot Client VM (mixed mode), Oracle Corporation
- Memory: 454482104 bytes (433 MB) / 519110656 bytes (495 MB) up to 1037959168 bytes (989 MB)
- JVM Flags: 2 total; -Xms512m -Xmx1024m
- LWJGL: 2.4.2
- OpenGL: Intel 945GM GL version 1.4.0 - Build 7.14.10.4926, Intel
- Is Modded: Definitely; 'forge,fml'
- Type: Client
- Texture Pack: Steelfeathers Enchanted Pack_v1.4.zip
- Profiler Position: N/A (disabled)
java.lang.NullPointerException
at cpw.mods.fml.common.network.FMLNetworkHandler.bindNetworkId(FMLNetworkHandler.java:261)
at cpw.mods.fml.common.network.ModIdentifiersPacket.execute(ModIdentifiersPacket.java:67)
at cpw.mods.fml.common.network.FMLNetworkHandler.handleFMLPacket(FMLNetworkHandler.java:89)
at cpw.mods.fml.common.network.FMLNetworkHandler.handlePacket250Packet(FMLNetworkHandler.java:59)
at asv.a(NetClientHandler.java:1288)
at ce.a(SourceFile:56)
at bb.b(TcpConnection.java:438)
at asv.d(NetClientHandler.java:99)
at asy.c(SourceFile:69)
at net.minecraft.client.Minecraft.l(Minecraft.java:1484)
at net.minecraft.client.Minecraft.J(Minecraft.java:831)
at net.minecraft.client.Minecraft.run(Minecraft.java:761)
at java.lang.Thread.run(Unknown Source)
--- END ERROR REPORT fdd63d71 ----------