Cannot open source file from std library

I’m looking through someone’s UE4 project, and they’re using things from the std library. The code compiles but there are lots of errors in the editor that say things like ‘cannot open source file “vector”’ and ‘namespace std has no member “uint64_t”’. The code compiles so maybe its an intellisense issue.

The project I’m looking at is GitHub - vblanco20-1/ECS_SpaceBattle: Huge space battle using an ECS library for the logic. Built on UE4

An example of him using the std library is here: ECS_SpaceBattle/ECS_Core.h at master · vblanco20-1/ECS_SpaceBattle · GitHub