绘制3D顶点时发生错误

我在Game Maker中尝试使用GPU渲染时遇到的一个错误。

在create事件中：

gpu_set_ztestenable(true);
gpu_set_zwriteenable(true);

vertex_format_begin();
vertex_format_add_position_3d();
vertex_format_add_texcoord();
vertex_format_add_colour();
vertex_format = vertex_format_end();

vbuffer = vertex_create_buffer();
vertex_begin(vbuffer, vertex_format)

var x1 = 400;
var y1 = 400;
var x2 = 600;
var y2 = 600;

vertex_position_3d(vbuffer, x1, y1, 100);
vertex_normal(vbuffer, 0, 0, 1);
vertex_texcoord(vbuffer, 0, 0);
vertex_color(vbuffer, c_white, 1);

vertex_position_3d(vbuffer, x2, y1, 100);
vertex_normal(vbuffer, 0, 0, 1);
vertex_texcoord(vbuffer, 0, 0);
vertex_color(vbuffer, c_white, 1);

vertex_position_3d(vbuffer, x2, y2, 100);
vertex_normal(vbuffer, 0, 0, 1);
vertex_texcoord(vbuffer, 0, 0);
vertex_color(vbuffer, c_white, 1);

vertex_end(vbuffer)

错误信息：未知错误