help!

[levishous]

Please help me! I keep getting the following error report when i try to launch tekkit classic. If anyone knows a solution please tell me!

java.lang.IllegalArgumentException: Slot 255 is already occupied by mffs.BlockForceField@161a226 when adding mffs.BlockForceField@dcac12

at pb.<init>(Block.java:251)

at pb.<init>(Block.java:284)

at agy.<init>(BlockContainer.java:13)

at mffs.BlockForceField.<init>(BlockForceField.java:30)

at mffs.mod_ModularForceFieldSystem.load(mod_ModularForceFieldSystem.java:115)

at cpw.mods.fml.common.modloader.ModLoaderModContainer.init(ModLoaderModContainer.java:356)

at cpw.mods.fml.common.Loader.modInit(Loader.java:273)

at cpw.mods.fml.common.Loader.initializeMods(Loader.java:628)

at cpw.mods.fml.client.FMLClientHandler.onLoadComplete(FMLClientHandler.java:223)

at net.minecraft.client.Minecraft.a(Minecraft.java:429)

at net.minecraft.client.Minecraft.run(Minecraft.java:738)

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

--- END ERROR REPORT cd239208 ----------

[muddiless]

It's a config error. Some other mods block Id is messing with modular forcefields. Try using id resolver or delete muffs or the mod causing the problem. Did you download any extra mods?