Description
You may see this error message in Intel® Quartus® Prime software version 18.0 when using LVDS SERDES in External PLL mode, and connecting two single channel RX modules to the IOPLL in Intel Cyclone® 10 GX devices.
Resolution
This problem is scheduled to be fixed in future release of the Intel Quartus Prime software. As a work around, instantiate one RX LVDS SERDES instance configured for 2 channels with the external IOPLL.