Camera Changes Proportions In Build

I have been having a problem with my camera whenever I build my standalone game (using Unity version 2017.3.0f3). The camera stays at its proper height, but it widens horizontally about 1/3 of a unit on each side, revealing areas of the scenes that aren’t supposed to be seen. This problem doesn’t happen in the Unity Editor. I have already made sure that the resolution (1200x800) in the build is the same as in the Unity Editor.

If it helps, here is a picture of my game being played in the Unity Editor:

And here is a picture of it being played as a .exe file:

Also, here are the resolution and presentation settings for my game:

Default Is Fullscreen: true

Default Is Native Resolution: false

Default Screen Width: 1200

Default Screen Height: 800

Mac Retina Support: true

Run In Background: false

Capture Single Screen: false

Display Resolution Dialog: Disabled

Use Player Log: false

Resizable Window: false

Mac Fullscreen Mode: Fullscreen Window

D3D11 Fullscreen Mode: Fullscreen Window

Visible In Background: true

Allow Fullscreen Switch: false

Force Single Instance: true

And none of the aspect ratios are supported (since Resolution Dialog is disabled).

Thanks in advance for your help!

I’m not really an expert on the subject, and I’m not really sure what could be causing it or how to fix it. However, you could work around it by setting up a script so that it covers the parts of the screen you shouldn’t be able to see. The simplest way to do this would probably be to just use a Rect to make some black rectangles on the edges of the camera view.

Although like I said I am no expert on the subject this is just a possible work around.