pylint a dictionnary wich designated as unsubscriptable object

I get this error when I use pylint on my code

path/script.py :34:47: E1136: Value 'dict_param' is unsubscriptable

On this dictionnary pylint said that it is is unsubscriptable

{'value1': {'value2': 0.5627031966752886}, 'value3': [0.97], 'value4': 'value6'}

Why I get this error ? Thank's