minecraft has chrashed

Tekkit Version 1.4.7

---- Minecraft Crash Report ----
// Ouch. That hurt

Time: 07.04.15 10:52
Description: Unexpected error

java.lang.IndexOutOfBoundsException
at com.eloraam.redpower.core.ItemExtended.d(ItemExtended.java:33)
at up.i(Item.java:458)
at up.l(Item.java:600)
at ur.r(SourceFile:334)
at atr.a(GuiIngame.java:406)
at ban.b(EntityRenderer.java:982)
at net.minecraft.client.Minecraft.J(Minecraft.java:884)
at net.minecraft.client.Minecraft.run(Minecraft.java:773)
at java.lang.Thread.run(Unknown Source)

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

– Head –
Stacktrace:
at com.eloraam.redpower.core.ItemExtended.d(ItemExtended.java:33)
at up.i(Item.java:458)
at up.l(Item.java:600)
at ur.r(SourceFile:334)
at atr.a(GuiIngame.java:406)

– Affected level –
Details:
Level name: MpServer
All players: 1 total; [ays['ExoPlot'/23498, l='MpServer', x=191,94, y=65,62, z=-153,41]]
Chunk stats: MultiplayerChunkCache: 441
Level seed: 0
Level generator: ID 00 - default, ver 1. Features enabled: false
Level generator options:
Level spawn location: World: (-112,64,252), Chunk: (at 0,4,12 in -7,15; contains blocks -112,0,240 to -97,255,255), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
Level time: 20245218 game time, 12280308 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: 115 total

The whole text is here: file:///G:/Technik/modpacks/tekkitlite/crash-reports/crash-2015-04-07_10.52.55-client.txt

every time i want to join a server of my friends i gget this error.

Personal E-Mail: exo.plot@gmail.com