Due to a problem in Intel® Quartus® Prime Pro Edition software version 20.3, you may see the following error when configuring Intel® Agilex™ devices over JTAG:
Error(18950): Device has stopped receiving configuration data
Error(18948): Error message received from device: Device is in configuration state
Error(209012): Operation failed
This problem is fixed starting in Intel® Quartus® Prime Pro Edition software version 20.4.