Can you rescue tablet that won't set?

Answer 1

As is the case of most confectionery when it won't set, you can probably reboil it, assuming it has not just gotten horribly stuck to the container it was supposed to be setting in.

However, that only applies to confectionery recipes which actually require cooking (e.g heating something to a specific temperature using a sugar thermometer), rather than the "no-cook" versions which work by gently heating a few things together until melted and combined.

If the recipe you were using was a sort of "no-cook" version, try sticking it in the freezer until it's set, break it apart and use as an ice-cream topping, or as a topping which slowly melts on hot desserts.