Adding Navmesh components makes visual studio cease to function

So I recently decided to learn how navmeshes work and went and watched a few tutorials on how to do it. Obviously one of the first things I needed was to put Navmeshcomponents into my game.

However apon doing this visual studio ceased to function correctly. If a project of mine has Navmeshcomponents inside of it's assets then VS does not recognize any of it's "using"s. (I'm sorry if I'm using the wrong terms btw.) When trying to declare a structure/datatype ex.
public "datatype" "name";
there are no datatypes in the selection that pertain to unity, almost like it's been severed from unity. Does anyone know what's going on here?

Any help would be appreciated.