Why is minecraft crashing

When I made the mod, registered everything, and so on, I should open a menu with the choice of the answer to the H key, but when I press it in minecraft itself, it crashes, why?
My main class code:
 

package com.example.examplemod;

import net.minecraft.client.Minecraft;
import net.minecraftforge.api.distmarker.Dist;
import net.minecraftforge.client.event.InputEvent;
import net.minecraftforge.eventbus.api.SubscribeEvent;
import net.minecraftforge.fml.common.Mod;
import org.lwjgl.glfw.GLFW;

@Mod("custommenu")

@Mod.EventBusSubscriber(Dist.CLIENT)
public class custommenu {
@SubscribeEvent
public void onKeyInput(InputEvent.KeyInputEvent event) {
if (event.getKey() == GLFW.GLFW_KEY_H && event.getAction() == GLFW.GLFW_PRESS) {
Minecraft.getInstance().setScreen(new CustomGui());
}
}
}

my second class where the code is written to open the menu:
 

package com.example.examplemod;

import com.mojang.blaze3d.matrix.MatrixStack;
import net.minecraft.client.Minecraft;
import net.minecraft.client.gui.screen.Screen;
import net.minecraft.client.gui.widget.button.Button;
import net.minecraft.util.ResourceLocation;
import net.minecraft.util.text.TranslationTextComponent;
import org.lwjgl.glfw.GLFW;


public class CustomGui extends Screen {
private final ResourceLocation background = new ResourceLocation("custommenu", "textures/gui/background.png");
private Button yesButton;
private Button noButton;
private Button laterButton;

public CustomGui() {
super(null);
}

@Override
protected void init() {
super.init();

yesButton = new Button(width / 2 - 100, height / 2 - 24, 200, 20, new TranslationTextComponent("Да"), button -> {
// Действия при выборе варианта "Да"
Minecraft.getInstance().setScreen(null);
});
noButton = new Button(width / 2 - 100, height / 2, 200, 20, new TranslationTextComponent("Нет"), button -> {
// Действия при выборе варианта "Нет"
Minecraft.getInstance().setScreen(null);
});
laterButton = new Button(width / 2 - 100, height / 2 + 24, 200, 20, new TranslationTextComponent("Позже"), button -> {
// Действия при выборе варианта "Позже"
Minecraft.getInstance().setScreen(null);
});

addButton(yesButton);
addButton(noButton);
addButton(laterButton);
}
@Override
public void render(MatrixStack matrixStack, int mouseX, int mouseY, float partialTicks) {
// Отображение текстуры
Minecraft.getInstance().getTextureManager().bind(background);
blit(matrixStack, 0, 0, 0, 0, width, height);

// Отображение кнопок
super.render(matrixStack, mouseX, mouseY, partialTicks);
}

@Override
public boolean keyPressed(int keyCode, int scanCode, int modifiers) {
if (keyCode == GLFW.GLFW_KEY_ESCAPE) {
Minecraft.getInstance().setScreen(null);
return true;
} else if (keyCode == GLFW.GLFW_KEY_H) {
// Открываем ваше меню с выбором ответа
Minecraft.getInstance().setScreen(new CustomGui());
return true;
}
return super.keyPressed(keyCode, scanCode, modifiers);
}

@Override
public boolean isPauseScreen() {
return false;
}
}