Load Errors(2): /Engine/Maps/Templates/Template_Default: Can't find file /Game/StarrySkyMaterial ...

I started messing around in unreal a few days ago and ended up playing with sky domes for a bit. I applied a texture to this BP_Sky_Sphere model, but I think I accidentally overwrote the configuration of the core engine asset (where I assumed it would only change it within my project). Now when I go to create a new empty C++ project, I get the following errors:

/Engine/EngineSky/BP_Sky_Sphere: Can’t find file for asset /Game/StarrySkyMaterial
/Engine/Maps/Templates/Template_Default: Can’t find file /Game/StarrySkyMaterial

Is there an easy fix to restore those files? Or will I need to reinstall the engine now?