LWJGL OpenGL-可以使用GlBegin渲染，但不能使用glDrawElements渲染

Question

我正在修改帧缓冲区，突然有东西坏了，一切恢复正常后我又回到状态，然后OpenGL突然停止了渲染。我可以碰巧glClearColor，也可以使用glBegin渲染东西，但是使用着色器和glDrawElements渲染时我什么也没有。我解除了每个帧缓冲区的绑定，检查了项目中的每个类，检查了着色器，什么也没有。

package test;

import org.lwjgl.LWJGLException;
import org.lwjgl.opengl.ContextAttribs;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.opengl.GL11;
import org.lwjgl.opengl.PixelFormat;
import org.lwjgl.util.vector.Vector2f;

public class Main {
    public static World world;
    public static GUIRenderer renderer;
    public static FrameBuffer buffer;

    public static void main(String[] args) throws InterruptedException {
        try {
            ContextAttribs attributes = new ContextAttribs(3,2).withForwardCompatible(true).withProfileCore(true);
            Display.setDisplayMode(new DisplayMode(800, 600));
            Display.setTitle("Test");
            Display.create(new PixelFormat(), attributes);
        } catch(LWJGLException e) {
            e.printStackTrace();
            System.exit(0);
        }

        world = new World();

        Vector2f[] vec = {new Vector2f(-1, 1), new Vector2f(-1, -1), new Vector2f(1, -1), new Vector2f(1, 1)};
        int[] indices = {0, 1, 2, 0, 2, 3};

        Mesh mesh = new Mesh();
        mesh.load(vec, indices);
        BasicShader2D shader = new BasicShader2D();
        renderer = new GUIRenderer();

        buffer = new FrameBuffer();

        GL11.glViewport(0, 0, Display.getWidth(), Display.getHeight());
        while(!Display.isCloseRequested()) {
            GL11.glClear(GL11.GL_COLOR_BUFFER_BIT);
            GL11.glClearColor(0.5f, 0, 0, 1);
            GL11.glEnable(GL11.GL_TEXTURE_2D);
            //buffer.bind();

            world.tick();

            renderer.render(mesh, shader);

            //buffer.unbind();
            GL11.glDisable(GL11.GL_TEXTURE_2D);

            Display.update();

            Thread.sleep(16);
        }

        world.delete();

        Display.destroy();
    }
}

//vertex
#version 150 core

uniform mat4 transformation;
uniform mat4 projection;
uniform mat4 view;

in vec3 pos;
in vec3 normal;

void main() {
    gl_Position = projection * view * transformation * vec4(pos, 1.0);
}

//fragment
#version 150 core
//#define PI 3.1415926535897932384626433832795

out vec4 color_out;

void main(){
    color_out = vec4(1.0, 1.0, 0.0, 1.0);
}