Question: I am trying to run an OpenAI Gym environment however I get the following error: import gym env = gym.make('Breakout-v0')  ERROR /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/ale_py/gym/environment.py:11: DeprecationWarning: Importing atari-py roms won't be supported in future releases of ale-py. import ale_py.roms as roms A.L.E: Arcade Learning Environment (version +a54a328) [Powered by Stella] Traceback (most recent call last): File "/Users/username/Desktop/OpenAI Gym Stuff/OpenAI_Exp.py", line 2, in <module> env = gym.make('Breakout-v0') File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/gym/envs/registration.py", line 200, in make return registry.make(id, **kwargs) File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/gym/envs/registration.py", line 105, in make env = spec.make(**kwargs) File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/gym/envs/registration.py", line 75, in make env = cls(**_kwargs) File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/ale_py/gym/environment.py", line 123, in __init__ self.seed() File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/ale_py/gym/environment.py", line 171, in seed raise error.Error( gym.error.Error: Unable to find game "Breakout", did you import Breakout with ale-import-roms? 

Answer: Code works for me with gym 0.18.0 and 0.19.0 but not with 0.20.0 You may downgrade it with pip install --upgrade gym==0.19.0  BTW: it may also need to install gym[atari] or gym[all] to have all elements to work.  Base on information in Release Note for 0.21.0 (which is not ready on pip but you can install from GitHub) there was some change in ALE (Arcade Learning Environment) and it made all problem but it is fixed in 0.21.0.  -The old Atari entry point that was broken with the last release and the upgrade to ALE-Py is fixed  But new gym[atari] not installs ROMs and you will need to use module AutoROM  -pip install gym[atari] no longer distributes Atari ROMs that the ALE (the Atari emulator used) needs to run the various games. The easiest way to install ROMs into the ALE has been to use AutoROM.   EDIT: Version 0.21.0 from GitHub works for me after installing (it may need program git for it) pip install --upgrade git+https://github.com/openai/gym pip install autorom AutoRom pip install --upgrade gym[atari]  AutoRom runs program which asks if you have license for ROMs and install ROMs in AutoROM/roms but I didn't have to move ROMs to other place. AutoROM will download the Atari 2600 ROMs. They will be installed to: /usr/local/lib/python3.8/dist-packages/AutoROM/roms Existing ROMs will be overwritten. I own a license to these Atari 2600 ROMs. I agree to not distribute these ROMs and wish to proceed: [Y/n]: Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/adventure.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/air_raid.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/alien.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/amidar.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/assault.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/asterix.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/asteroids.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/atlantis.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/atlantis2.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/backgammon.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/bank_heist.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/basic_math.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/battle_zone.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/beam_rider.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/berzerk.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/blackjack.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/bowling.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/boxing.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/breakout.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/carnival.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/casino.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/centipede.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/chopper_command.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/combat.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/crazy_climber.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/crossbow.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/darkchambers.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/defender.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/demon_attack.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/donkey_kong.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/double_dunk.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/earthworld.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/elevator_action.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/enduro.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/entombed.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/et.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/fishing_derby.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/flag_capture.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/freeway.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/frogger.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/frostbite.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/galaxian.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/gopher.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/gravitar.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/hangman.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/haunted_house.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/hero.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/human_cannonball.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/ice_hockey.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/jamesbond.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/journey_escape.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/joust.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/kaboom.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/kangaroo.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/keystone_kapers.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/king_kong.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/klax.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/koolaid.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/krull.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/kung_fu_master.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/laser_gates.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/lost_luggage.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/mario_bros.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/maze_craze.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/miniature_golf.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/montezuma_revenge.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/mr_do.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/ms_pacman.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/name_this_game.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/othello.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/pacman.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/phoenix.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/pitfall.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/pitfall2.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/pong.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/pooyan.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/private_eye.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/qbert.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/riverraid.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/road_runner.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/robotank.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/seaquest.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/sir_lancelot.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/skiing.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/solaris.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/space_invaders.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/space_war.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/star_gunner.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/superman.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/surround.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/tennis.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/tetris.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/tic_tac_toe_3d.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/time_pilot.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/trondead.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/turmoil.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/tutankham.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/up_n_down.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/venture.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/video_checkers.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/video_chess.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/video_cube.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/video_pinball.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/warlords.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/wizard_of_wor.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/word_zapper.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/yars_revenge.bin Installed /usr/local/lib/python3.8/dist-packages/AutoROM/roms/zaxxon.bin Done!   After installation this code works for me without error and without DeprecationWarning. import gym import ale_py print('gym:', gym.__version__) print('ale_py:', ale_py.__version__) env = gym.make('Breakout-v0')  and it gives gym: 0.21.0 ale_py: 0.7.1 A.L.E: Arcade Learning Environment (version +b7b0c1a) [Powered by Stella]