Shokurov's minimal discrepancy conjecture

Let $V$ be a normal affine variety of complex dimension $n$ with an isolated singularity at $0$ that is numerically $\mathbb{Q}$-Gorenstein. Write $\operatorname{min.disc}(V,0)$ for its minimal discrepancy. Shokurov's conjecture.

$$\operatorname{min.disc}(V,0)\leq n-1$$

Moreover, the singularity is smooth if and only if $\operatorname{min.disc}(V,0)=n-1$. This conjecture relates minimal discrepancy to smoothness and is open for varieties of complex dimension greater than $3$.