Beginner Question: want to use Vector3 but Visual Studios doesnt know it

Its like already said in the title. I want to create a normal Vector3 within my C# file but the the system kind of doesnt know what Vector3 is. And yes I implemented
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
in the begining of my file.
Please send help.

 

That sounds odd. Can you please post the code.

 

If you don't have any autocomplete/etc in your Visual Studio, try these steps.

If those don't work post your code, you might be doing something strange there.

 

Wow somehow now the same code is working. I dont know wtf happend there but ok.
But there is still one small problem. In any video I have seen that the Vector3 lights up blue but it doesnt do that in my file. Does anybody know why?

 

Strange. Did you check your external tools in preferences?
Also, is your scripting runtime version set to .NET4.x equivalent?

Otherwise I suggest rebooting both Unity and Visual Studio altogether.

 

Sorry but i dont know what .NET4.x is. Could you please explain this to me? and how I change it xD
and i checked the external tools, I selected game developing with unity.

 

Go to project settings - Player and then other settings. You'll see scripting runtime version under configuration.

 

Well... this option isnt even there xD
i gooogled it and it shoulb be there

 

I downloaded Unity 2019.1 now and set this option to .NET 4. x Equivalent and its somehow working now. Does anybody have an idea how i can make it work in unity 2019.3?