You may experience that the Opgaaf Werkelijk Rendement (OWR) declaration for 2020 is rejected with the error: 'identifier not set'. This occurs if the question 'Heeft uw cliënt een fiscaal partner?' is answered with 'No'. The OWR for other years and with a Fiscal partner for 2020 are not affected. We have identified the issue and are working on a fix. Our apologies for the inconvenience.