The file probably contains non-ANSI characters: if an “end-of-file” character is encountered, which should not be present in an ANSI file, this error could occur. Please make sure your csv file contains ANSI characters only. If you want to convert it and / or correct it, here is what you can do:

1. Create a new .txt file with Notepad (it is very important that the file is created from scartch)
2. Open the old file with Notepad and copy all the text
3. Paste the text in the newly created file
4. Import the newly created file

This should correct ANSI problems in most situations. Obviously this is an emergency trick only: configure the program you are exporting from so that it creates ANSI-compliant files.