As others have pointed out there is an important distinction to be made between determinism and predictability. However, "Norton's dome" is a good example of a

As others have pointed out there is an important distinction to be made between determinism and predictability. However, "Norton's dome" is a good example of a situation in which Newtonian mechanics might arguably be non-deterministic: https://www.pitt.edu/~jdnorton/papers/DomePSA2006_final.pdf https://www.pitt.edu/~jdnorton/papers/DomePSA2006_final.pdf https://en.wikipedia.org/wiki/Norton%27s_dome https://en.wikipedia.org/wiki/Norton%27s_dome