The primary taxpayer’s SSN on this return has been used as the a spouse’s SSN on another tax return filed and accepted in which Married Filing Separately is the filing status. If one of the spouses already filed using Married Filing Separately as the filing status, the other spouse cannot file a separate return using a filing status of Single, Married Filing Jointly, or Qualifying Widower.
Fix #1: Sign into your RapidTax account and update your filing status by following the on-screen instructions. You will then be able to resubmit your tax return for filing.