Runtime error & Index error

[Skyhigh8131]

Describe the bug
I read "Foundations of Deep Reinforcement Learning"
and I ran
python run_lab.py slm_lab/spec/benchmark/reinforce/reinforce_cartpole.json reinforce_cartpole train
to practice REINFORCE Algorithm

but I got runtime error and index error

To Reproduce

1. OS and environment: Ubuntu 20.04 and I use it in vmware
2. SLM Lab git SHA (run git rev-parse HEAD to get it): 9102ff9
3. spec file used: reinforce_cartpole_spec.json

Error logs