UnicodeDecodeError: 'utf-8' codec can't decode byte 0x91 in position 15: invalid start byte code example

Example 1: 'utf-8' codec can't decode byte 0x85 in position 715: invalid start byte

import pandas as pd
data = pd.read_csv(filename, encoding= 'unicode_escape')

Example 2: 'utf-8' codec can't decode byte 0xff in position 0: invalid start byte

with open(file, newline='', encoding="utf16") as MyFile: