Minecraft Forge 1.12.2 FileNotFound

Sooo i have tried to ust show up a picture , but it get a FileNotFoundException. Why ?

public class Gui extends GuiScreen {
    int guiheight = 200;
    int guiwidht = 200;

    public void initGui() {
    }

    public void drawScreen(int mouseX, int mouseY, float partialTicks) {
        drawDefaultBackground();
        mc.getTextureManager().bindTexture(new ResourceLocation(Main.MOD_ID,"gui/img.png"));
        int offsetfromscreenLeft = (width - guiwidht) / 2;
        drawTexturedModalRect(offsetfromscreenLeft, 2,0,0,guiwidht,guiheight);
        super.drawScreen(mouseX, mouseY, partialTicks);
    }
}

and my picture is in

Project/src/main/resources/asses/main/gui/img.png

public static final String MOD_ID = "main";