Got AssertionError while loading trained autonomous driving models.

What I did in Jupyter Notebook:

import os
import gym
from stable_baselines3 import PPO
from stable_baselines3.common.vec_env import DummyVecEnv
from stable_baselines3.common.evaluation import evaluate_policy

environment_name = "CarRacing-v0"
env = gym.make(environment_name)
env = DummyVecEnv([lambda: env])

ppo_path = os.path.join("Training", "Saved Models", "PPO_428k_Driving_model")

model = PPO.load(ppo_path, env)

When I run the last section, I got this AssertionError:

Wrapping the env in a VecTransposeImage.
---------------------------------------------------------------------------
AssertionError                            Traceback (most recent call last)
d:\GitHub\autonomous-driving\ad_notebook.ipynb Cell 14 in <cell line: 2>()
      [1](vscode-notebook-cell:/d%3A/GitHub/autonomous-driving/ad_notebook.ipynb#X16sZmlsZQ%3D%3D?line=0) # model.save(ppo_path)
----> [2](vscode-notebook-cell:/d%3A/GitHub/autonomous-driving/ad_notebook.ipynb#X16sZmlsZQ%3D%3D?line=1) model = PPO.load(ppo_path, env)

File c:\Users\user\anaconda3\envs\RLstation\lib\site-packages\stable_baselines3\common\base_class.py:747, in BaseAlgorithm.load(cls, path, env, device, custom_objects, print_system_info, force_reset, **kwargs)
    745 model.__dict__.update(data)
    746 model.__dict__.update(kwargs)
--> 747 model._setup_model()
    749 # put state_dicts back in place
    750 model.set_parameters(params, exact_match=True, device=device)

File c:\Users\user\anaconda3\envs\RLstation\lib\site-packages\stable_baselines3\ppo\ppo.py:168, in PPO._setup_model(self)
    165 super()._setup_model()
    167 # Initialize schedules for policy/value clipping
--> 168 self.clip_range = get_schedule_fn(self.clip_range)
    169 if self.clip_range_vf is not None:
    170     if isinstance(self.clip_range_vf, (float, int)):

File c:\Users\user\anaconda3\envs\RLstation\lib\site-packages\stable_baselines3\common\utils.py:91, in get_schedule_fn(value_schedule)
     89     value_schedule = constant_fn(float(value_schedule))
     90 else:
---> 91     assert callable(value_schedule)
     92 return value_schedule

AssertionError:

So, I trained a model with $428000$ timesteps. And loaded that. That model worked perfectly. I cannot understand what is the reason of this error occurring. I also downloaded the PPO_2m_Driving_model.zip and also got the same AssertionError. Do anyone know what is the problem?