What this means: Your file uploaded successfully, but it only contains a header row with no actual data records beneath it.
Why this might happen: Your payroll system may have generated an export file even though there were no records to include; for instance, if no workers were eligible for this pay period.
What to do
Check whether there genuinely should be records in this submission
If there shouldn't, no action is needed, but you may want to adjust your payroll process to avoid creating empty exports in future
If there should be records, review your payroll export settings and re-export