ID:186009 Transmitter or receiver pin "<name>" must use differential I/O standard -- Fitter will automatically assign <name> standard to pin

CAUSE: You assigned a non-differential I/O standard to the specified differential I/O transmitter or receiver pin. The pin can use only a differential I/O standard. The Fitter will automatically assign the specified differential I/O standard to the transmitter or receiver pin.

ACTION: No action is required. To avoid receiving this message in the future, delete the assignment, or change the assignment to a differential I/O standard.