It’s a small problem, but this guidein section “4.8, creating projectile, setting the mesh” uses
StaticMesh->RelativeLocation = FVector(0.0f, 0.0f, -37.5f);
StaticMesh->RelativeScale3D = FVector(0.75f, 0.75f, 0.75f);
When in current engine version(4.26) it was replaced with setters:
StaticMesh->SetRelativeLocation(FVector(0.0f, 0.0f, -37.5f));
StaticMesh->SetRelativeScale3D(FVector(0.75f, 0.75f, 0.75f));
Also, in section 5.4:
Instigator->Controller
instead of
GetInstigator()->Controller
Same about instigator in section 6.4 as well.