Visual Studio not properly configured?

I'm very new to Unity, and tries to follow Brackey's fantastic RPG-tutorial.

I wonder if something is wrong with my Visual Studio setup, because I can't get VS to do the magic Brackey can.

For instance - when he writes:

Code (csharp):

1.  
2. [...]
3. using UnityEngine.AI;
4. [...]
5. NavMeshAgent agent;
6.  

the component name "NavMeshAgent" changes color, and then he get the methods listed each time he uses "agent." in the code.

Another example:

Code (csharp):

1.  
2. Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
3. RaycastHit hit;
4.  

writing "hit." later won't show me the methods, and all code is just standard color (except some keywords).

The scripts works all right though. I'm using a fresh installation of the latest version on a Windows-box.

How can I get VS to behave?

 

Guess I found the answer myself.

This has to be a bug, but if I select the file in VS' Solution Explorer on the right, switch the file's property "Build Action" from "Compile" to "None" - and then back again to "Compile", everything works!