Setting up Nav Mesh

Idk been messing with it for a while. Can't get the blue to cover the entire map.
I want most of this walkable for my AI.

 

Have you tried increasing the step height as suggested in the warning ?

 

Thanks for the response.
Ya ofcourse. same amount of blue area shown when I do that.
Should I not pay attention to the blue area?

 

I've tried every possible setting combination.
I finally got this far though.
My guys get stuck though. They are just walking a straight line to and they don't even try to avoid a non blue area.

 

Could it be cause im updating the Target inside Update?

Code (csharp):

1.  
2.     private void Update(){
3.  
4.  
5.         float distance = Vector3.Distance (transform.position, Target.transform.position);
6.         if(distance > 4f) {
7.             agent.destination = Target.transform.position;
8.         }
9.  
10.  
11.     }
12.  

 

Never mind I fixed this issue. It was the controller that I use that I had to adjust as well.