Program: 34200
Project: 34200
Buggy source:
@Override public boolean onBlockActivated(World world,int x,int y,int z,EntityPlayer player,int faceHit,float par7,float par8,float par9){
  if (player.isSneaking()) {
    return false;
  }
 else {
    if (!world.isRemote && player instanceof EntityPlayerMP) {
      if (!(world.getTileEntity(x,y,z) instanceof TileEntityMachine)) {
        return false;
      }
      TileEntityMachine tileEntityMachine=(TileEntityMachine)world.getTileEntity(x,y,z);
      ItemStack playerStack=player.getCurrentEquippedItem();
      NBTTagCompound stackNBT=null;
      NBTTagCompound cmNBT=null;
      if (playerStack != null) {
        if (playerStack.hasTagCompound()) {
          stackNBT=playerStack.getTagCompound();
          if (stackNBT.hasKey("String_Node_Str")) {
            cmNBT=stackNBT.getCompoundTag("String_Node_Str");
          }
        }
        if (playerStack.getItem() instanceof ItemPersonalShrinkingDevice || ((cmNBT != null && cmNBT.hasKey("String_Node_Str")) && cmNBT.getBoolean("String_Node_Str"))) {
          CompactMachines.instance.machineHandler.teleportPlayerToMachineWorld((EntityPlayerMP)player,tileEntityMachine);
        }
 else         if (FluidContainerRegistry.isEmptyContainer(playerStack)) {
          FluidUtils.emptyTankIntoContainer(tileEntityMachine,player,tileEntityMachine.getFluid(faceHit),ForgeDirection.getOrientation(faceHit));
        }
 else         if (FluidContainerRegistry.isFilledContainer(playerStack)) {
          FluidUtils.fillTankWithContainer(tileEntityMachine,player,ForgeDirection.getOrientation(faceHit));
        }
 else         if (tileEntityMachine.isUpgraded == false && playerStack.getItem() == Reference.upgradeItem) {
          tileEntityMachine.isUpgraded=true;
          tileEntityMachine.markDirty();
          world.markBlockForUpdate(x,y,z);
          playerStack.stackSize--;
        }
 else         if (playerStack.getItem() == ModItems.quantumentangler) {
          if (!ConfigurationHandler.allowEntanglement) {
            player.addChatMessage(new ChatComponentTranslation("String_Node_Str"));
            return true;
          }
          if (stackNBT != null && stackNBT.hasKey("String_Node_Str") && stackNBT.hasKey("String_Node_Str")) {
            if (tileEntityMachine.coords != -1) {
              player.addChatMessage(new ChatComponentTranslation("String_Node_Str"));
            }
 else             if (tileEntityMachine.isUpgraded == false) {
              player.addChatMessage(new ChatComponentTranslation("String_Node_Str"));
            }
 else {
              int size=stackNBT.getInteger("String_Node_Str");
              if (size != tileEntityMachine.meta) {
                player.addChatMessage(new ChatComponentTranslation("String_Node_Str"));
              }
 else {
                int coords=stackNBT.getInteger("String_Node_Str");
                tileEntityMachine.coords=coords;
                if (stackNBT.hasKey("String_Node_Str")) {
                  tileEntityMachine.setCustomName(stackNBT.getString("String_Node_Str"));
                }
                tileEntityMachine.readInterfacesFromNBT(stackNBT);
                tileEntityMachine.markDirty();
                playerStack.stackSize--;
              }
            }
          }
 else           if (tileEntityMachine.isUpgraded && tileEntityMachine.coords != -1) {
            NBTTagCompound nbt=new NBTTagCompound();
            nbt.setInteger("String_Node_Str",tileEntityMachine.coords);
            nbt.setInteger("String_Node_Str",tileEntityMachine.meta);
            tileEntityMachine.addInterfacesToNBT(nbt);
            nbt.setString("String_Node_Str",tileEntityMachine.getCustomName());
            playerStack.setTagCompound(nbt);
          }
 else {
            if (tileEntityMachine.coords == -1) {
              player.addChatMessage(new ChatComponentTranslation("String_Node_Str"));
            }
 else             if (!tileEntityMachine.isUpgraded) {
              player.addChatMessage(new ChatComponentTranslation("String_Node_Str"));
            }
          }
        }
 else {
          player.openGui(CompactMachines.instance,GuiId.MACHINE.ordinal(),world,x,y,z);
        }
      }
 else {
        player.openGui(CompactMachines.instance,GuiId.MACHINE.ordinal(),world,x,y,z);
      }
    }
    return true;
  }
}

Fixed version (ground truth):
@Override public boolean onBlockActivated(World world,int x,int y,int z,EntityPlayer player,int faceHit,float par7,float par8,float par9){
  if (player.isSneaking()) {
    return false;
  }
 else {
    if (!world.isRemote && player instanceof EntityPlayerMP) {
      if (!(world.getTileEntity(x,y,z) instanceof TileEntityMachine)) {
        return false;
      }
      TileEntityMachine tileEntityMachine=(TileEntityMachine)world.getTileEntity(x,y,z);
      ItemStack playerStack=player.getCurrentEquippedItem();
      NBTTagCompound stackNBT=null;
      NBTTagCompound cmNBT=null;
      if (playerStack != null) {
        if (playerStack.hasTagCompound()) {
          stackNBT=playerStack.getTagCompound();
          if (stackNBT.hasKey("String_Node_Str")) {
            cmNBT=stackNBT.getCompoundTag("String_Node_Str");
          }
        }
        if (playerStack.getItem() instanceof ItemPersonalShrinkingDevice || ((cmNBT != null && cmNBT.hasKey("String_Node_Str")) && cmNBT.getBoolean("String_Node_Str"))) {
          CompactMachines.instance.machineHandler.teleportPlayerToMachineWorld((EntityPlayerMP)player,tileEntityMachine);
        }
 else         if (FluidContainerRegistry.isEmptyContainer(playerStack)) {
          FluidUtils.emptyTankIntoContainer(tileEntityMachine,player,tileEntityMachine.getFluid(faceHit),ForgeDirection.getOrientation(faceHit));
        }
 else         if (FluidContainerRegistry.isFilledContainer(playerStack)) {
          FluidUtils.fillTankWithContainer(tileEntityMachine,player,ForgeDirection.getOrientation(faceHit));
        }
 else         if (tileEntityMachine.isUpgraded == false && playerStack.getItem() == Reference.upgradeItem) {
          tileEntityMachine.isUpgraded=true;
          tileEntityMachine.markDirty();
          world.markBlockForUpdate(x,y,z);
          playerStack.stackSize--;
        }
 else         if (playerStack.getItem() == ModItems.quantumentangler) {
          if (!ConfigurationHandler.allowEntanglement) {
            player.addChatMessage(new ChatComponentTranslation("String_Node_Str"));
            return true;
          }
          if (stackNBT != null && stackNBT.hasKey("String_Node_Str") && stackNBT.hasKey("String_Node_Str")) {
            if (tileEntityMachine.coords != -1) {
              player.addChatMessage(new ChatComponentTranslation("String_Node_Str"));
            }
 else             if (tileEntityMachine.isUpgraded == false) {
              player.addChatMessage(new ChatComponentTranslation("String_Node_Str"));
            }
 else {
              int size=stackNBT.getInteger("String_Node_Str");
              if (size != tileEntityMachine.meta) {
                player.addChatMessage(new ChatComponentTranslation("String_Node_Str"));
              }
 else {
                int coords=stackNBT.getInteger("String_Node_Str");
                tileEntityMachine.coords=coords;
                if (stackNBT.hasKey("String_Node_Str")) {
                  tileEntityMachine.setCustomName(stackNBT.getString("String_Node_Str"));
                }
                tileEntityMachine.readInterfacesFromNBT(stackNBT);
                tileEntityMachine.markDirty();
                WorldUtils.updateNeighborAEGrids(world,x,y,z);
                playerStack.stackSize--;
              }
            }
          }
 else           if (tileEntityMachine.isUpgraded && tileEntityMachine.coords != -1) {
            NBTTagCompound nbt=new NBTTagCompound();
            nbt.setInteger("String_Node_Str",tileEntityMachine.coords);
            nbt.setInteger("String_Node_Str",tileEntityMachine.meta);
            tileEntityMachine.addInterfacesToNBT(nbt);
            nbt.setString("String_Node_Str",tileEntityMachine.getCustomName());
            playerStack.setTagCompound(nbt);
          }
 else {
            if (tileEntityMachine.coords == -1) {
              player.addChatMessage(new ChatComponentTranslation("String_Node_Str"));
            }
 else             if (!tileEntityMachine.isUpgraded) {
              player.addChatMessage(new ChatComponentTranslation("String_Node_Str"));
            }
          }
        }
 else {
          player.openGui(CompactMachines.instance,GuiId.MACHINE.ordinal(),world,x,y,z);
        }
      }
 else {
        player.openGui(CompactMachines.instance,GuiId.MACHINE.ordinal(),world,x,y,z);
      }
    }
    return true;
  }
}