Buildcraft error

[ajcool1050]

so me and my friends where playeing and all of the suddun the server just laggs out and it wount start back up and this error happens

17:20:34 [sEVERE] java.lang.NullPointerException

17:20:34 [sEVERE] at net.minecraft.server.ItemStack.doMaterialsMatch(ItemStack.java:243)

17:20:34 [sEVERE] at ee.TileCondenser.extractItem(TileCondenser.java:539)

17:20:34 [sEVERE] at buildcraft.transport.pipes.PipeItemsWood.checkExtract(PipeItemsWood.java:111)

17:20:34 [sEVERE] at buildcraft.transport.pipes.PipeItemsWood.doWork(PipeItemsWood.java:90)

17:20:34 [sEVERE] at buildcraft.transport.TileGenericPipe.doWork(TileGenericPipe.java:159)

17:20:34 [sEVERE] at buildcraft.api.PowerProvider.update(PowerProvider.java:52)

17:20:34 [sEVERE] at buildcraft.transport.TileGenericPipe.l_(TileGenericPipe.java:108)

17:20:34 [sEVERE] at net.minecraft.server.World.tickEntities(World.java:1182)

17:20:34 [sEVERE] at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:534)

17:20:34 [sEVERE] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:441)

17:20:34 [sEVERE] at net.minecraft.server.ThreadServerApplication.run(SourceFile:465)

17:20:34 [sEVERE] Unexpected exception

java.lang.NullPointerException

at net.minecraft.server.ItemStack.doMaterialsMatch(ItemStack.java:243)

at ee.TileCondenser.extractItem(TileCondenser.java:539)

at buildcraft.transport.pipes.PipeItemsWood.checkExtract(PipeItemsWood.java:111)

at buildcraft.transport.pipes.PipeItemsWood.doWork(PipeItemsWood.java:90)

at buildcraft.transport.TileGenericPipe.doWork(TileGenericPipe.java:159)

at buildcraft.api.PowerProvider.update(PowerProvider.java:52)

at buildcraft.transport.TileGenericPipe.l_(TileGenericPipe.java:108)

at net.minecraft.server.World.tickEntities(World.java:1182)

at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:534)

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:441)

at net.minecraft.server.ThreadServerApplication.run(SourceFile:465)

>

pls help me we had alot of stuff on the world and if i start a new world it work why is this happaning pls get back to me a soon a posible tanks so much

[truthseeker83]

It may be related to this.. i see your errors had "Condenser and Pipes mentioned in it.... http://forums.technicpack.net/index.php/topic,5663.0.html

[ajcool1050]

ya but i had no condensors in the world just baseic pipes but ill try to get it to work