Prime of bad reduction (awaiting review)

For an abelian variety $A$ of dimension $g$ over a number field $K$, a prime of bad reduction (for $A$) is a prime $\mathfrak{p}$ of $K$ for which the reduction of $A$ modulo $\mathfrak{p}$ is not an abelian variety of dimension $g$ over the residue field at $\mathfrak{p}$. The number of primes of bad reduction is always finite; these are precisely the primes that divide the conductor of $A$.