Why does the Quartus Prime software fail to open? - Why does the Quartus Prime software fail to open? Description The Quartus® Prime software may fail to open if the Quartus registry file has been corrupted. Resolution To work around this problem, use the below commands to reset Quartus registry files: quartus - regserver quartus -reset_desktop Custom Fields values: ['novalue'] Troubleshooting novalue False ['novalue'] ['FPGA Dev Tools Quartus® Prime Software Pro'] novalue 15.1 ['Programmable Logic Devices'] ['novalue'] ['novalue'] ['novalue']