This is not a dangerous issue but because the cerys mod spawns asteroids flying around the moon itself and makes them drop their crushable variant, this mod does not work with it.

It's not crashing but whenever the asteroid spawns (which is a good sign) it can actually be attacked but when it gets destroyed like other asteroids, it does not drop it's crushable item variant, making copper unobtainable and you waste ammo on those meteorites.

I am uncertain whether I should post it here or on the cerys discussion page so if this issue is out of your hands, please let me know so I can inform them instead.

Thanks for reporting this, while the spawning is handled by the Cerys mod, I'm the one that added the code for it, so I'll create a PR for the fix shortly

Late update but I tested this and cannot reproduce. If anyone else has this issue, please update here, and state what version of Cerys, Cupric Asteroids, and what minimum set of mods you notice this issue with.