Repro steps:

1. Open provided project
2. Click on "File" -> "Build Settings" -> "Player Settings"
3. In the Inspector window go down to "Scripting Runtime Version" and change it from "Stable" to "Experimental"
4. Click "Restart" on the new dialog box that just appeared
5. After the restart click on "File" -> "Build Settings" -> "Build"
6. Notice that while the project is building some Warnings appear in the Console window
7. Notice that after the project has been built some Errors appear in the Console window

Expected result: The project builds without any Warning or Error messages
Actual result: The project builds,but with Warning and Error messages

Reproduced with: 2017.2.0a1, 2017.1.0b6
Did not reproduce on: 5.6.1p1 (The project has errors so I can't build it)