AssertionError: Observation space (None) does not inherit from gym.spaces.Space

[yixiaoer]

run python -u train_agent.py --agent_type simple --game_dir ./games/twc --game_name *.ulx --difficulty_level easy as instruction, but there is error:
"The registry.env_specs property along with EnvSpecTree is deprecated. Please use registry directly as a dictionary instead."
Traceback (most recent call last):
File "train_agent.py", line 300, in
scores, norm_scores, moves = play(myagent, opt, random_action=random_action)
File "train_agent.py", line 38, in play
opt.mode, opt.verbose)
File "/code/commonsense-rl/games/dataset.py", line 19, in get_game_env
env = gym.make(env_id)
File "/root/miniconda3/envs/twc/lib/python3.7/site-packages/gym/envs/registration.py", line 601, in make
env = PassiveEnvChecker(env)
File "/root/miniconda3/envs/twc/lib/python3.7/site-packages/gym/wrappers/env_checker.py", line 25, in init
check_observation_space(env.action_space)
File "/root/miniconda3/envs/twc/lib/python3.7/site-packages/gym/utils/passive_env_checker.py", line 145, in check_observation_space
f"Observation space ({observation_space}) does not inherit from gym.spaces.Space"
AssertionError: Observation space (None) does not inherit from gym.spaces.Space