该输出表示您的输入不在GB18030编码。

That output means that your input is NOT in GB18030 encoding.

还：请检查并仔细检查您查看您的文件：程序使用哪种编码来打开文件，特别是输入文件。通常，文本文件（和CSV文件）都没有附带显示其编码的元数据，因此编辑者必须进行猜测，并且猜测很容易是错误的。

Also: please check and double-check how you view your files: what encoding does the program use that opens the files, specifically the input file. Usually text files (and CSV files) don't come with metadata attached to them that shows their encoding, so the editors have to guess and that guess can easily be wrong.