PLL_T2_CLKOUT3、PLL_T2_CLKOUT4 and PLL_T2_FBp/CLKOUT1、PLL_T2_FBp/CLKOUT2

Hi I have a PLL to drive two PLL output pins,such as PLL_T2_CLKOUT3 and PLL_T2_CLKOUT4.And this is ok. While changing to PLL_T2_FBp/CLKOUT1、PLL_T2_FBp/CLKOUT2,Quartus has the warning: "fe...