I'm not sure who I should report this error to. If it's you or Buildcraft Team but getting the following Error with:

This only happens in a Server environment. Client environment is fine.

Futurepack 1.11.2 version 25.2.9
Buildcraft 1.11.2 version 7.99.3
Forge Version 13.20.0.2296

This is the Error:
Description: Exception in server tick loop

net.minecraftforge.fml.common.LoaderExceptionModCrash: Caught exception from BC Transport (buildcrafttransport)
Caused by: java.lang.NoSuchMethodError: futurepack.common.block.deco.BlockMetalSlap.idPicked(Lnet/minecraft/world/World;Lnet/minecraft/util/math/BlockPos;)Lnet/minecraft/block/Block;
at futurepack.common.block.deco.BlockMetalSlap.getPickBlock(BlockMetalSlap.java:58)
at buildcraft.transport.plug.FacadeStateManager.getRequiredStack(FacadeStateManager.java:62)
at buildcraft.transport.plug.FacadeStateManager.postInit(FacadeStateManager.java:92)
at buildcraft.transport.BCTransport.init(BCTransport.java:77)
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.minecraftforge.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:641)
at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74)
at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304)
at com.google.common.eventbus.EventBus.post(EventBus.java:275)
at net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:252)
at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:230)
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 com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74)
at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304)
at com.google.common.eventbus.EventBus.post(EventBus.java:275)
at net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:147)
at net.minecraftforge.fml.common.Loader.initializeMods(Loader.java:828)
at net.minecraftforge.fml.server.FMLServerHandler.finishServerLoading(FMLServerHandler.java:109)
at net.minecraftforge.fml.common.FMLCommonHandler.onServerStarted(FMLCommonHandler.java:333)
at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:215)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:442)
at java.lang.Thread.run(Unknown Source)

Buildcraft FacadeStateManager tryes to acces methods from a futurepack blocjk wish doesnt exists... this will be interesting to solve...

Have you also notified buildcraft?

I have not, would you like me to?

Yes as I am not shure how to fix this. It would be nice to know what buildcraft is trying to do here.

BuildCraft/BuildCraft#3580

BuildCraft attempts to find the ItemStack that best represents the block to use as the recipe when making a facade for that block. It does this by calling Block.getPickStack, as that's the closest thing to getting what item is required for that block (unlike getDrops or others this returns the correct item for things like bookshelves and leaves)

This looks like the method BlockMetalSlap.idPicked is annotated with @SideOnly(Side.CLIENT), but I can't check as I can't find a source for the file (or its a closed-source project)

Ahh getPickBlock was CLIENT Side Only but that changed so alot of stuff were still Client Side Only on my side.
This build should fix the issue.

Looks like that did the trick Nicely. Thanks for the speedy response!