TypeError: string indices must be integers in pybamm library file

[sreehari33]

params = pybamm.ParameterValues(chemistry = pybamm.parameter_sets.Chen2020) # calling parameters of chen
from pybamm
File "C:\Users\AppData\Local\Programs\Python\Python39\lib\site-packages\pybamm\parameters\parameter_values.py", line 65, in init
self.update_from_chemistry(chemistry)
File "C:\Users\AppData\Local\Programs\Python\Python39\lib\site-packages\pybamm\parameters\parameter_values.py", line 160, in update_from_chemistry
base_chemistry = chemistry["chemistry"]
TypeError: string indices must be integers

hi, I've been stuck with this error for the past few days.The error seems to be in the pybamm library files, tried making some changes but still the error persists.please help.

[valentinsulzer]

Try just ParameterValues("Chen2020")