Does chocolate go bad??

[ProfessorGAC]

11. Very Unlikely

There's an abundance of sugar & very little moisture, so it won't support microbial growth. Lack of bacteria also makes the chance the milk protein can curdle is extremely low.
In addition, theobromine, the alkaloid that contributes most to chocolate's flavor, is a close relative to caffeine.
To bugs & other tiny critters, it's toxic.
What can happen is that the fats can separate from the cocoa solids, leaving a white bloom on the surface. But, that's only a physical, not chemical change.
My technical opinion is that chocolate will be fine to eat.
Courtesy of your friendly, neighborhood chemist.