Re: When importing a list I get this message: "no header row found for file"?
It's a best practice to never rely on auto-detect when importing .csv or .txt files into Marketo. Do you get this same error when you select "Comma separated values"? If so, then there's another bug that has been appearing more often for us - and that's the need to give the system time to recognize a newly created "list" before importing names into it. We often need to give it about 5 minutes and do a refresh before we can import names into the list.