I'm getting a warning that says "Newlines detected in data, output file might not be readable by other tools." What causes this, and is it anything to worry about?
It means there are new lines somewhere in your dataset. Depending on your data this may or may not be okay.
I guess my question was - if you have done nothing that would have added new lines, why would this message appear?
Then the new-lines must be in the data originally, if you profile it in a browse tool you should be able to figure out where they are. It also might not be a problem at all depending on your use case.