Program: 161332
Project: 161332
Buggy source:
@Override public boolean onBlockActivated(World world,int x,int y,int z,EntityPlayer player,int par6,float par7,float par8,float par9){
  if (player.isSneaking()) {
    return false;
  }
  int metadata=world.getBlockMetadata(x,y,z);
  TileEntity te=world.getTileEntity(x,y,z);
  IMultiblockPart part=null;
  MultiblockControllerBase controller=null;
  if (te instanceof IMultiblockPart) {
    part=(IMultiblockPart)te;
    controller=part.getMultiblockController();
  }
  if (isCasing(metadata) || isPowerTap(metadata) || isComputerPort(metadata)) {
    if (player.getCurrentEquippedItem() == null) {
      if (controller != null) {
        Exception e=controller.getLastValidationException();
        if (e != null) {
          player.addChatMessage(new ChatComponentText(e.getMessage()));
          return true;
        }
      }
 else {
        player.addChatMessage(new ChatComponentText("String_Node_Str"));
        return true;
      }
    }
    return false;
  }
  if (!world.isRemote && (isAccessPort(metadata) || isCoolantPort(metadata))) {
    ItemStack currentEquippedItem=player.getCurrentEquippedItem();
    if (StaticUtils.Inventory.isPlayerHoldingWrench(player)) {
      if (te instanceof TileEntityReactorCoolantPort) {
        TileEntityReactorCoolantPort cp=(TileEntityReactorCoolantPort)te;
        cp.setInlet(!cp.isInlet(),true);
        return true;
      }
 else       if (te instanceof TileEntityReactorAccessPort) {
        TileEntityReactorAccessPort cp=(TileEntityReactorAccessPort)te;
        cp.setInlet(!cp.isInlet());
        return true;
      }
    }
 else     if (isCoolantPort(metadata)) {
      return false;
    }
  }
  if (isController(metadata) && (controller == null || !controller.isAssembled())) {
    return false;
  }
  if (!world.isRemote) {
    player.openGui(BRLoader.instance,0,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 par6,float par7,float par8,float par9){
  if (player.isSneaking()) {
    return false;
  }
  int metadata=world.getBlockMetadata(x,y,z);
  TileEntity te=world.getTileEntity(x,y,z);
  IMultiblockPart part=null;
  MultiblockControllerBase controller=null;
  if (te instanceof IMultiblockPart) {
    part=(IMultiblockPart)te;
    controller=part.getMultiblockController();
  }
  if (isCasing(metadata) || isPowerTap(metadata) || isComputerPort(metadata)) {
    if (player.getCurrentEquippedItem() == null) {
      if (controller != null) {
        Exception e=controller.getLastValidationException();
        if (e != null) {
          player.addChatMessage(new ChatComponentText(e.getMessage()));
          return true;
        }
      }
 else {
        player.addChatMessage(new ChatComponentText("String_Node_Str"));
        return true;
      }
    }
    return false;
  }
  if (!world.isRemote && (isAccessPort(metadata) || isCoolantPort(metadata))) {
    if (StaticUtils.Inventory.isPlayerHoldingWrench(player)) {
      if (te instanceof TileEntityReactorCoolantPort) {
        TileEntityReactorCoolantPort cp=(TileEntityReactorCoolantPort)te;
        cp.setInlet(!cp.isInlet(),true);
        return true;
      }
 else       if (te instanceof TileEntityReactorAccessPort) {
        TileEntityReactorAccessPort cp=(TileEntityReactorAccessPort)te;
        cp.setInlet(!cp.isInlet());
        return true;
      }
    }
 else     if (isCoolantPort(metadata)) {
      return false;
    }
  }
  if (isController(metadata) && (controller == null || !controller.isAssembled())) {
    return false;
  }
  if (!world.isRemote) {
    player.openGui(BRLoader.instance,0,world,x,y,z);
  }
  return true;
}