move NavMesh.asset to another empty Unity file, and I can't see the it.

It's quite simple.
I want to test how much memory Unity uses to simply load NavMesh, so I made a test.
Here are my steps:
1.Create two empty projects, called "A" and "B".
2.Create a huge plane in A project(about 1200(x)*1(y)*1200(z)), set the plane to Navigation Static, then click Bake.
3.After completely baked, delete the plane in A's hierachy, click its NavMesh.asset, I can see the whole NavMesh.

4.I copy the NavMesh.asset from A and paste it to B, and make sure the path is the same with its original path.However, I can't see the NavMesh in the Scene View。

Besides, I pack two projects into .exe files, and run them, the memory of A's .exe taken in my Task Manager of is larger than the other one, which probably means only the first one loads the NavMesh, but there is no difference between the two projects at all, anyone knows it? Thanks in advance

 

Turns out it's the problem about .meta file or .scene file, reopen Unity, and it goes back to normal, so stupid, sorry for interruption