Hey,
I’d need to see what your Component setup looks like for this Blueprint, but I think you might simply be missing a primitive component as root and so it throws this error. I would guess you don’t even need ProjectileComponent for something that’s falling, has physics turned on, and uses an Add Impulse on Begin Play. If you want, post some images of your Components tab. You can also and attach .uasset file for Blueprint if you don’t mind letting me take a look to be sure.