I have ploblem seems this. Can you talk about it some more. I have entity with whow I want to trade. I created a GuiTrade class that extends GuiContainer, ContainerTrade that extends Container and as inventory I used InventoryMerchant. When I displayed gui with (from entity class, from proccessInteract)

Minecraft.getMinecraft().displayGuiScreen(new GuiTrade(player, this));

I had a normal gui with only strange item move. If you take item, some another has been disappeared. After I shall know about player.openGui(mod_instance, 0, world, posX, posY, posZ) and IGuiHandler. But it works only with blocks and I don't know answer now. Can you help me?

 

 

public class GuiHandler implements IGuiHandler {

    @Nullable
    @Override
    public Object getServerGuiElement(int id, EntityPlayer player, World world, int x, int y, int z) {
        if (id == 0) {
            return new ContainerTrade(player.inventory /*merchant needs*/);
        }
        return null;
    }

    @Nullable
    @Override
    public Object getClientGuiElement(int id, EntityPlayer player, World world, int x, int y, int z) {
        if (id == 0) {
            return new GuiTrade(player /*merchant needs*/);
        }
        return null;
    }
}

Sorry for misunderstanding, english isn't my native language. Could you explain to me some more. This is my GuiHandler. I need a merchant instance for trade gui and container constructors. You said that instead of x, y, z coordinates I should send entity ID, aren't you? Maybe I saying something wrong. Correct me if needs, please.

I found solution at this link. 

 

42 minutes ago, Rey838 said:

You said that instead of x, y, z coordinates I should send entity ID, aren't you?

I don't understand right away because this way in unusual. Thanks very much!