[Python] Why can I not create a vertex array with ModernGL?

I'm trying to make a game with pygame, and I'm using moderngl to use shaders. However, I'm getting constant issues trying to create moderngl objects. Currently, I cannot create multiple moderngl Vertex Arrays. It's weird, I'm able to create one but when I go to create the second or third the code returns a moderngl Error. I'm new to ModernGL so it could be a simple issue that I'm not seeing.

Here's my shader manager that manages the loading and post_processing of shaders:

class ShaderManager:
def __init__(self, ctx: moderngl.Context, initial_size: tuple[int,int]):
self.ctx = ctx
# 1 quad VBO (x,y) + (u,v)
verts = np.array([
-1, 1, 0.0, 0.0,
-1, -1, 0.0, 1.0,
1, 1, 1.0, 0.0,
1, -1, 1.0, 1.0,
], dtype='f4')
self.quad_vbo = ctx.buffer(verts.tobytes())

self.programs: dict[str, moderngl.Program] = {}
self.vaos: dict[str, moderngl.VertexArray] = {}
self.fbo_cache: dict[tuple[int,int], tuple] = {}

# pre-allocate initial FBO textures
self._ensure_fbo(initial_size)

def load(self, name: str, vert_source: str | Path, frag_source: str | Path):
"""Compile and register a shader program from file paths or raw source strings."""
if isinstance(vert_source, Path) or isinstance(vert_source, str) and Path(vert_source).exists():
vs = Path(vert_source).read_text(encoding='utf-8')
else:
vs = vert_source # treat as raw GLSL string

if isinstance(frag_source, Path) or isinstance(frag_source, str) and Path(frag_source).exists():
fs = Path(frag_source).read_text(encoding='utf-8')
else:
fs = frag_source # treat as raw GLSL string

prog = self.ctx.program(vertex_shader=vs, fragment_shader=fs)
self.programs[name] = prog

def _ensure_fbo(self, size: tuple[int,int]):
"""Make textures+FBO for this resolution if missing."""
if size in self.fbo_cache:
return
w,h = size
in_tex = self.ctx.texture((w,h), 4, alignment=1)
out_tex = self.ctx.texture((w,h), 4, alignment=1)
for t in (in_tex, out_tex):
t.filter = (moderngl.NEAREST, moderngl.NEAREST)
t.swizzle = 'BGRA'
fbo = self.ctx.framebuffer(color_attachments=[out_tex])
self.fbo_cache[size] = (in_tex, out_tex, fbo)

def _get_vao(self, name: str):
"""Lazily create a VAO that feeds quad_vbo into in_vert/in_uv."""
if name not in self.vaos:
prog = self.programs[name]
# Explicitly tell moderngl how the VBO is structured: 2 floats (pos), 2 floats (uv)
vao = self.ctx.vertex_array(
prog,
[(self.quad_vbo, '2f 2f', 'in_vert', 'in_uv')]
)
self.vaos[name] = vao
return self.vaos[name]

def post_process(self, passes: list[str], scene: pygame.Surface) -> pygame.Surface:
"""
Run each named pass in order over `scene`, returning the final.
Internally uses two ping-pong FBOs sized to scene.get_size().
"""
size = scene.get_size()
self._ensure_fbo(size)
in_tex, out_tex, fbo = self.fbo_cache[size]

# upload initial
data = pygame.image.tostring(scene, 'RGBA', False)
in_tex.write(data)
in_tex.use(location=0)

current_tex = in_tex
for name in passes:
prog = self.programs[name]
# bind
prog['tex'].value = 0
if 'time' in prog:
prog['time'].value = time.time() % 1000

# render into out_tex
fbo.use()
self.ctx.clear(0.0,0.0,0.0,1.0)
vao = self._get_vao(name)
vao.render(mode=moderngl.TRIANGLE_STRIP)

# swap
current_tex, out_tex = out_tex, current_tex
fbo = self.ctx.framebuffer(color_attachments=[out_tex])
out_tex.use(location=0)

# readback final
final_data = current_tex.read()
return pygame.image.frombuffer(final_data, size, 'RGBA')


However, it's returning the following error:

PS C:\Users\infamoose\Documents\coding\spellsmithAgain> python main.py
pygame 2.6.1 (SDL 2.28.4, Python 3.11.9)
Hello from the pygame community. https://www.pygame.org/contribute.html
Traceback (most recent call last):
File "C:\Users\infamoose\Documents\coding\spellsmithAgain\main.py", line 39, in <module>
run_game()
File "C:\Users\infamoose\Documents\coding\spellsmithAgain\main.py", line 35, in run_game
instanceManager(screen, settingsManager(), ctx)
File "C:\Users\infamoose\Documents\coding\spellsmithAgain\utility\instanceManager.py", line 39, in __init__
main_menu(screen, self)
File "C:\Users\infamoose\Documents\coding\spellsmithAgain\screens\main_menu.py", line 184, in main_menu
base.run()
File "C:\Users\infamoose\Documents\coding\spellsmithAgain\utility\screen_utility\baseScreen.py", line 271, in run
self.draw(virtual_mouse)
File "C:\Users\infamoose\Documents\coding\spellsmithAgain\utility\screen_utility\baseScreen.py", line 246, in draw
surf = sm.post_process(["invert", "blur"], surf)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\infamoose\Documents\coding\spellsmithAgain\utility\shaderManager.py", line 93, in post_process
vao = self._get_vao(name)
^^^^^^^^^^^^^^^^^^^
File "C:\Users\infamoose\Documents\coding\spellsmithAgain\utility\shaderManager.py", line 61, in _get_vao
vao = self.ctx.vertex_array(
^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\infamoose\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.11_qbz5n2kfra8p0\LocalCache\local-packages\Python311\site-packages\moderngl\__init__.py", line 1901, in vertex_array
return self._vertex_array(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\infamoose\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.11_qbz5n2kfra8p0\LocalCache\local-packages\Python311\site-packages\moderngl\__init__.py", line 1922, in _vertex_array
res.mglo, res._glo = self.mglo.vertex_array(
^^^^^^^^^^^^^^^^^^^^^^^
_moderngl.Error: cannot create vertex array

Continue reading...