ID:186158 Can't place clock signal "<name>" due to conflicting location requirements or incompatible I/O standards

CAUSE: The specified clock signal must be promoted to use global clocks due to gigabit transceiver block (GXB) transmitter PLL duplication, fan-outs placed outside the quad, or an incompatible I/O standard. At the same time, the clock signal must be locked to the dedicated GXB transmitter PLL clock input pins due to the use of a predivider in the GXB transmitter PLL or GXB receiver PLL, or use of the 1.5-V PCML I/O standard. The predivider is only available in the dedicated GXB transmitter PLL clock input pins. The I/O standards supported at the dedicated clock input pins are 1.5-V PCML, LVDS , and LVPECL.

ACTION: Modify the design to avoid GXB transmitter PLL duplication, delete the fan-outs placed outside the quad, change the I/O standard assignment, or avoid using a predivider in the GXB transmitter PLL or GXB receiver PLL.