gizzyboy5

Actually I just resolved the problem, I was having an ID Conflict, with a vanilla item, also the server for me at least does start in offline mode however in your error log look for ID conflicts mine was with a record.

When attempting to run my mod, the single player will run fine however when attempting to connect to a custom server the client crashes and, I get the following crash report. Minecraft Crash Report ---- // Daisy, daisy... Time: 12/19/13 1:10 AM Description: Ticking screen java.lang.NullPointerException at java.net.URLEncoder.encode(Unknown Source) at net.minecraft.client.multiplayer.NetClientHandler.urlEncode(NetClientHandler.java:336) at net.minecraft.client.multiplayer.NetClientHandler.sendSessionRequest(NetClientHandler.java:318) at net.minecraft.client.multiplayer.NetClientHandler.handleServerAuthData(NetClientHandler.java:299) at net.minecraft.network.packet.Packet253ServerAuthData.processPacket(Packet253ServerAuthData.java:51) at net.minecraft.network.TcpConnection.processReadPackets(TcpConnection.java:462) at net.minecraft.client.multiplayer.NetClientHandler.processReadPackets(NetClientHandler.java:281) at net.minecraft.client.multiplayer.GuiConnecting.updateScreen(GuiConnecting.java:51) at net.minecraft.client.Minecraft.runTick(Minecraft.java:1580) at net.minecraft.client.Minecraft.runGameLoop(Minecraft.java:910) at net.minecraft.client.Minecraft.run(Minecraft.java:838) at net.minecraft.client.main.Main.main(Main.java:93) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at net.minecraft.launchwrapper.Launch.launch(Launch.java:131) at net.minecraft.launchwrapper.Launch.main(Launch.java:27) A detailed walkthrough of the error, its code path and all known details is as follows: --------------------------------------------------------------------------------------- -- Head -- Stacktrace: at java.net.URLEncoder.encode(Unknown Source) at net.minecraft.client.multiplayer.NetClientHandler.urlEncode(NetClientHandler.java:336) at net.minecraft.client.multiplayer.NetClientHandler.sendSessionRequest(NetClientHandler.java:318) at net.minecraft.client.multiplayer.NetClientHandler.handleServerAuthData(NetClientHandler.java:299) at net.minecraft.network.packet.Packet253ServerAuthData.processPacket(Packet253ServerAuthData.java:51) at net.minecraft.network.TcpConnection.processReadPackets(TcpConnection.java:462) at net.minecraft.client.multiplayer.NetClientHandler.processReadPackets(NetClientHandler.java:281) at net.minecraft.client.multiplayer.GuiConnecting.updateScreen(GuiConnecting.java:51) -- Affected screen -- Details: Screen name: net.minecraft.client.multiplayer.GuiConnecting Stacktrace: at net.minecraft.client.Minecraft.runTick(Minecraft.java:1580) at net.minecraft.client.Minecraft.runGameLoop(Minecraft.java:910) at net.minecraft.client.Minecraft.run(Minecraft.java:838) at net.minecraft.client.main.Main.main(Main.java:93) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at net.minecraft.launchwrapper.Launch.launch(Launch.java:131) at net.minecraft.launchwrapper.Launch.main(Launch.java:27) -- System Details -- Details: Minecraft Version: 1.6.4 Operating System: Windows 8 (x86) version 6.2 Java Version: 1.7.0_45, Oracle Corporation Java VM Version: Java HotSpot Client VM (mixed mode), Oracle Corporation Memory: 985251688 bytes (939 MB) / 1046937600 bytes (998 MB) up to 1046937600 bytes (998 MB) JVM Flags: 3 total; -Xincgc -Xmx1024M -Xms1024M AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used Suspicious classes: FML and Forge are installed IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0 FML: MCP v8.11 FML v6.4.45.953 Minecraft Forge 9.11.1.953 4 mods loaded, 4 mods active mcp{8.09} [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available FML{6.4.45.953} [Forge Mod Loader] (bin) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available Forge{9.11.1.953} [Minecraft Forge] (bin) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available GizLabs{v1} [GizLabs Core] (bin) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available Launched Version: 1.6 LWJGL: 2.9.0 OpenGL: Intel® HD Graphics 4000 GL version 4.0.0 - Build 9.17.10.2867, Intel Is Modded: Definitely; Client brand changed to 'fml,forge' Type: Client (map_client.txt) Resource Pack: Default Current Language: English (US) Profiler Position: N/A (disabled) Vec3 Pool Size: ~~ERROR~~ NullPointerException: null any idea what this would occur?