Prefab stop working after build (in exe and editor)

Unity Engine
1

Hi,
I’m trying to create a small prototyp and I’m using Unity Network Lobby asset for this.

This lobby is a prefab with lobby menu on canvas.
It works fine until I build the game. After I build, when I’m still in the editor and I’m pressing play - prefab is gone.
While the game is running I can’t put this back on the scene ( I can do it with other prefabs ). The same issue is in the exe file, I see game scene without lobby prefab.

Prefab is going to work again in the editor after Unity restart but I can’t get correct built version.

I’m using 2017.1.0f3

2

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