I have used Kicad for a while but have never run into such an ERC error until now, see JPG.
It claims the power and the flag are both power out?
But one is programmed as IN the other OUT, I even tried copying the flag and power symbols from the 5v versions and the same thing.
I don't get the fault with 5v?
Anyone have an idea?
The error jumps from the 5v to the 15v flags also.
They are isolated supplies with separate ground.
Max.

 

Found it by trial and error, you can only identify one power flag even though more than one power source is used.
Max.