The message implies that you didn't fill out the API (advance passenger information) details, or that an error was made when entering these details (DOB [date of birth] and/or Gender are indicated as mismatched)

You won't be able to check in until these errors/mismatches are corrected - the details entered must match with the details on the passport number entered.

If OLCI is already open this is probably something you will now have to correct at a check-in desk at the airport rather than over the phone