I Expected that the command "/fill 1178 3 815 1184 3 1039 minecraft:wool 15" would do exactly what it had been doing for my High School build (typed with different cordinates and blocks though), and extend my road out to the point on the Z axis where i said to

Instead it gave me the message "cannot place blocks outside the world". and don't try to tell me that 1039 on the Z axis is outside of the world, because if it was there wouldn't be a village about 100 blocks later

Steps to Reproduce:
1. type the command following command on a superflat world
/fill 1178 3 815 1184 3 1039 minecraft:wool 15.
2. unless it only bugs out on some worlds and not others... you should get the message "cannot place blocks outside of the world"
3. ...