I’m trying to set up a reinforcement learning environment but running into issues. Here’s what I’m attempting:
import gym
game_env = gym.make('CartPole-v1')
When I execute this code, I encounter a lengthy traceback that ends with:
OSError: [WinError 126] The specified module could not be found
The error seems to originate from the atari_py package when gym tries to load the environment. The stack trace shows it’s failing to load ale_c.dll during the import process. I’m running this on Windows with Python 3.7. Has anyone encountered similar issues when working with gym environments? What’s the best way to resolve this module loading problem?
Ah, the classic Windows DLL nightmare. Been there way too many times.
Gym tries to register ALL environments when you import it - even the Atari ones that need atari_py. You just want CartPole, but it’s still trying to load that broken ale_c.dll.
Here’s what works:
import gym
# Bypass the Atari registration errors
gym.envs.registry.env_specs = {k: v for k, v in gym.envs.registry.env_specs.items() if 'atari' not in k.lower()}
game_env = gym.make('CartPole-v1')
Better option - just switch to gymnasium (the maintained fork):
pip install gymnasium
import gymnasium as gym
game_env = gym.make('CartPole-v1')
I moved all my projects to gymnasium last year after hitting these same dependency issues. It’s actively maintained and doesn’t try installing every environment by default.
If you’re stuck with old gym, try the Microsoft Visual C++ Redistributable. But seriously, just use gymnasium. You’ll thank yourself later.
That video’s a solid RL intro if you’re new to reinforcement learning.
This happens because atari_py has dependency issues on Windows. Even though you just want CartPole, gym tries to register ALL environments when it starts up - including Atari games that need the broken ale_c.dll file. I ran into this exact problem six months ago on my Windows setup. Just uninstall atari_py with pip uninstall atari_py and you’ll be good to go. CartPole doesn’t need it anyway. If you want Atari games later, reinstall the Microsoft Visual C++ 2015-2019 Redistributable, but for now just ditch atari_py - it’s the easiest fix.
i faced this too! gym’s auto-loading all envs is a pain, right? try reinstalling with pip install gym[classic_control] - it avoids the ale_c.dll mess and keeps it lightweight.
