ID:176500 Can't place nDQS I/O "<name>" in location <name> -- nDQS I/O pin requires DQSMUX resource location that is occupied by a DQS I/O pin not associated with this nDQS I/O pin

CAUSE: The Fitter could not place the specified nDQS I/O pin in the specified location because the DQSMUX resource required by the nDQS pin is already occupied by a different DQS I/O pin. You may have made location assignments which resulted in the Fitter attempting to place the nDQS I/O pin in the specified location. If you did not make a location assignment, the specified location represents the last location in which the Fitter attempted to place the specified nDQS I/O pin.

ACTION: If you made a location assignment to the specified nDQS I/O pin, remove the assignment if possible. Otherwise, remove the location assignments to the DQ I/O pins or the DQS I/O pin associated with the specified nDQS I/O pin. If this does not result in a successful fit, compile the design targeting a larger device.