Description
You will see this error if you try and use a transceiver Rx pin as a reference clock when using Quartus® II software version 12.1 and earlier on Cyclone® V GX devices.
Resolution
You should use a dedicated transceiver REFCLK pin.
Using an Rx pin a transceiver reference clock on Cyclone V GX devices will be supported in a future version of the Quartus II software.