ID:186168 Can't place GXB transmitter or receiver channel "<name>" to location <name> because its CRUCLK input port <name> is assigned to a location which cannot route to the GXB transmitter or receiver channel

CAUSE: You assigned the CRUCLK input port of the specified gigabit transceiver block (GXB) transmitter or receiver channel to a location. However, the Fitter cannot place the GXB transmitter or receiver channel at the specified location because its CRUCLK input port cannot route to the GXB transmitter or receiver channel due to the user assignment.

ACTION: Delete or change the location assignment on the CRUCLK input port.