I just had a realization… Unreal uses VS as a compiler… this is probably a VS issue. The fact you have a log output tells me you are already inside the Unreal Editor. Do you have a 2D sidescroller map that shows up inside the editor that looks like this
If so, in the World Outliner, on the right side of your Unreal screen by default scroll through the list till you see TP_2DSieScrollerCharacter and click on it. This will populate the details window just below the World Outliner. At the top are a list of inherited components and the last in the list is CharacterMovement(Inherited). Right click that and click Open CharacterMovementComponent.h … this should open the header file in VS. Lets see if we can at least get that far.