Load pickle error

Hello All…need help…I got an error when i load the pickle file.

error = UnpicklingError: invalid load key, '\x00'.

My code is below:

pkl_file_path = r"C:\Users\Practicals\PickleLoad\overall.pkl"
with open(pkl_file_path, 'rb') as pklfile:
    load_pipeline_overall = pickle.load(pklfile)

Really appreciate any advice on how to fix this…thanks

Please show the code that writes the file.
I suspect how the file is written is not compatible with how it is read.