I can't see my First Person Controller

Hi ! I follow this tutorial to make my first fps: tutorial fps
There’s my problem that I can’t fix…
I think I did exactly the same as in the video, but when I launch the game, I can’t see if the animations work because my First Person Controller disappear.
Here, I put my gun “CZ805” as a child of WeaponRecoilHolder who is a child of the Main Camera

I add a screen on top.
I did’t finished my text, When CZ805 is a child of WeaponRecoilHolder who is a child of the Main Camera < first Person Controller, the First Person Controller disappear whereas when I put simply the weapon as a child of the Main Camera, the First Person Controller appears but the animations doesn’t work.

Here is my Player Controller Script: PlayerController Script

I hope someone might help me (I’m french so I’m sorry if I said something weird)