Steps to reproduce the issue:
1. Open attached project.
2. Build the project for Windows ("CTRL"+"B").
3. Back to the Editor and open scene named "Prototype".
4. Enter the Play mode.
5. In the "Game" window press "Dedicated Server (S)" button.
6. Launch the build and press "Client (C)" button.
7. Back to the Editor.

Actual result:
The Play mode pauses and "Console" window outputs error message when the client tries to connect.

InvalidProgramException: Invalid IL code in PlayerSetup:InitilizePlayer (): IL_0042: call 0x0600001b
PlayerSetup.Start () (at Assets/Prototype/scripts/PlayerSetup.cs:12)

Expected result:
The client should connect successfully.

Reproduced with:
5.3.6p2, 5.4.0f3.

Cannot reproduce with:
5.1.5f1, 5.2.5f1 (because "The type or namespace name `SceneManagement' does not exist in the namespace `UnityEngine'.")
5.5.0a5 (because "APIUpdater encountered some issues and was not able to finish.
API updating failed. Check previous console messages.
Error building Player because scripts have compiler errors in the editor")