i have the same problem. python 3.8, tensorflow 2.4.1
with "detector = FER(mtcnn=True)" i will get the AttributeError: module 'keras.utils.generic_utils' has no attribute 'to_snake_case'
of course the function works without the mtcnn=True setting. But then OpenCV's Haar Cascade classifier is used. how can I use fer with the mtcnn -network?