Something borked in my update as when i logged in the floor went black shadows even after rebaking the lighting.
The cause i found when i tried to save the projectile blueprint after adding a sphere. It would not save.
To fix this simply delete the projectile_BP and then remake it from right clicking the projectile cpp.
Once you have done this you can open the BP and add the sphere with saving afterwards.
This will also fix any lighting issues on your terrain.