Error(129015): Output port REGOUTHI on atom "<file name>", which is a twentynm_ddio_in primitive, is not legally connected and/or configured - Error(129015): Output port REGOUTHI on atom "<file name>", which is a twentynm_ddio_in primitive, is not legally connected and/or configured Description You might see this error in the Intel® Quartus® Prime Standard Edition Software version 16.1 when you set register mode to DDIO and enable Half Rate Logic in Altera GPIO IP for Intel® Arria® 10 devices. Resolution This problem is fixed starting with the Intel® Quartus® Prime Standard Edition Software version 18.1. Custom Fields values: ['novalue'] Troubleshooting FB: 482851; False ['ASMI Parallel IP'] ['FPGA Dev Tools Quartus® Prime Software Pro'] 18.1 16.1 ['Arria® 10 FPGAs and SoCs'] ['novalue'] ['novalue'] ['novalue']