def METHOD_NAME(pal_file_path: str) -> Path:
    """
    Convert a string path to Pathlib path.
    If None, use default path and print warning message.
    If file is missing, print error.
    :param pal_file_path: path to .pal file
    :return: path as pathlib Path
    """
    default_pal_file_path = get_script_directory() / 'palettes' / 'palgen.pal'
    if pal_file_path is None:
        print(f'WARNING: Palette file not specified - falling back to default palette file {str(default_pal_file_path)}')
        return default_pal_file_path
    elif not Path(pal_file_path).exists():
        print(f'WARNING: Palette file {str(Path(pal_file_path))} does not exist - falling back to default palette file {str(default_pal_file_path)}')
        return default_pal_file_path
    else:
        return Path(pal_file_path)