Problem Ticking screen issue when People Logging into my Mindcrack 8.1.0 server

[Justjones'n]

Ok This happens every time I update the server and nothing I usually do is working to fix the problem. Does anyone know of a way to fix this or a way to prevent this from happening again?
Minecraft has stopped running because it encountered a problem; Ticking screen
-- Head --
Stacktrace:
at asw.d(SourceFile:35)
at asw.b(SourceFile:23)
at net.minecraft.client.Minecraft.a(Minecraft.java:2072)
at net.minecraft.client.Minecraft.a(Minecraft.java:2023)
at cpw.mods.fml.client.FMLClientHandler.disconnectIDMismatch(FMLClientHandler.java:529)
at cpw.mods.fml.common.FMLCommonHandler.disconnectIDMismatch(FMLCommonHandler.java:464)
at cpw.mods.fml.common.network.ModIdMapPacket.execute(ModIdMapPacket.java:89)
at cpw.mods.fml.common.network.FMLNetworkHandler.handleFMLPacket(FMLNetworkHandler.java:102)
at cpw.mods.fml.common.network.FMLNetworkHandler.handlePacket250Packet(FMLNetworkHandler.java:67)
at ayh.a(NetClientHandler.java:1483)
at di.a(SourceFile:59)
at com.mumfrey.liteloader.core.HookPluginChannels.a(HookPluginChannels.java:99)
at cg.b(TcpConnection.java:458)
at ayh.d(NetClientHandler.java:240)
at ayk.c(GuiConnecting.java:49)
-- Affected screen --
Screen name: ~~ERROR~~ NullPointerException: null
-- Affected level --
Details:
Level name: MpServer
All players: 1 total; [ays['Thorism'/368352, l='MpServer', x=4725.70, y=114.50, z=-12336.70]]
Chunk stats: MultiplayerChunkCache: 5
Level seed: 0
Level generator: ID 00 - default, ver 1. Features enabled: false
Level generator options:
Level spawn location: World: (232,64,180), Chunk: (at 8,4,4 in 14,11; contains blocks 224,0,176 to 239,255,191), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 92537176 game time, 6617981 day time
Level dimension: 0
Level storage version: 0x00000 - Unknown?
Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
Forced entities: 1 total; [ays['Thorism'/368352, l='MpServer', x=4725.70, y=114.50, z=-12336.70]]
Retry entities: 0 total; []
Stacktrace:
at ayp.a(WorldClient.java:439)
at net.minecraft.client.Minecraft.b(Minecraft.java:2401)
at net.minecraft.client.Minecraft.run(Minecraft.java:787)
at java.lang.Thread.run(Unknown Source)

 

[Francis Baster]

Yes, when you updated the server you may not have updated your server's config folder. 'disconnectIDMismatch' is caused by server and client running different configs in my experience.