Make sure the file uses the UTF-8 character set. Remove any non-printable characters. IBM has a history of not supporting ASCII well so the file may not be what you think it is.
A file without commas will not work as a Splunk lookup file.
To know if you're using the correct option requires knowing what you're trying to accomplish. What do you want to do with this file? Do you want to index it, make it into a lookup file, or something else?
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