ID:18496 The Output <name> in pin location <name> (pad_<number>) is too close to PLL clock input pin (<name>) in pin location <name> (pad_<number>)

CAUSE: You assigned the specified output pin to the specified pin location in the target device that is too close to the PLL clock input pin in the specified location.

ACTION: Assign the output pin to a different location that is not directly on the left or right of the PLL clock input pin.