Error: Pin cannot have a calibrated on-chip termination user assignment

Description

You may see this error because the Quartus® II software versions 7.2 and earlier incorrectly allows you to make series 25 or 50 ohm on-chip termination (OCT) with calibration assignments, when targeting Arria® GX devices. 

This problem is scheduled to be fixed in a future release of the Quartus II software.