Starting with Intel® Quartus® Prime Pro Edition Software version 21.1, the secure device manager (SDM) in Intel® Stratix® 10 no longer supports the EPCQ-L device. When a design for Intel® Stratix® 10 device is generated with Intel® Quartus® Prime Pro Edition Software version 21.1 or later, the design fails to access an EPCQ-L device using the Mailbox Client Intel® FPGA IP, the Serial Flash Mailbox Client Intel® FPGA IP, the SDM Debug Toolkit, and the Configuration Debugger tool.
Use Intel® Quartus® Prime Pro Edition Software version 20.4 or earlier to generate a design for Intel® Stratix® 10 device, when the design accesses an EPCQ-L device using the Mailbox Client Intel® FPGA IP, the Serial Flash Mailbox Client Intel® FPGA IP, the SDM Debug Toolkit, and the Configuration Debugger tool.