This is not following Newton's laws

Can you please explain what does it mean "This is not following laws"?

Okay. So, watch what happens. So, we apply Newton's laws and we apply them to… Oh! William Herschel discovers planet Uranus by accident, okay? Uranus's the planet just beyond Saturn, so by accident and this is after Newton's laws of gravity are published. So, now we're tracking the orbit of Uranus you should know, this is not following Newton's laws, it's got some deviation. So, maybe we found the limits, the distance limit over which Newton's laws would apply, that'd be interesting. But other people said: "That Newton was so badass, it must work', okay?