My problem about a ERROR in cassiemujoco.py

[SB-Moloo]

Hello! In my environment. Function "generate_perlin(x_res, y_res)" in line 50 and function "CassieState()" int line 80 is Error. And where is the main function to run this project. I can run the file "cassietest.py". But i can't make it walking. What' more,I get a error called "Could not find body named left-heel" after running the file "cassietest_depth.py" and I have ran the "cassietest.py" before.