def METHOD_NAME(filename):
    invalid = False
    # pattern = re.compile("[^\x00-\x7F]") #do ot want to replace printable chars like €¢ etc
    pattern = re.compile(
        "[\u200B-\u200E\uFEFF\u202c\u202D\u2063\u2062]"
    )  # zero width characters
    error_message = ""
    for i, line in enumerate(open(filename)):
        for match in re.finditer(pattern, line):
            err = f"Unicode char in FILE {filename} Line {i+1}: {match.group().encode('utf-8')}"
            error_message += f"{err}\n"
            LOGGER.debug(err)
            invalid = True
    if invalid:
        raise ValueError(error_message)