UnicodeDecodeError: 'utf-8' codec can't decode byte 0x80 in position 0: invalid start byte

This error indicates that the Python interpreter is trying to decode a byte string using the UTF-8 codec, but the byte string contains a byte (0x80) that is not a valid start byte in UTF-8 encoding.

To fix this error, you can try to decode the byte string using a different codec that supports the character encoding of the byte string. For example, you can try decoding the byte string using the 'latin-1' codec:

byte_string = b'\x80...'
decoded_string = byte_string.decode('latin-1')

Alternatively, you can try to fix the source of the byte string so that it is properly encoded in UTF-8 before it is passed to the Python interpreter.