Game works in editor, but breaks when exported.

My current projects is a little 2D platformer. It functions fine in the editor, but when I build it I run into one of two issues. If I run it at my native resolution (1920 x 1080), after the unity logo it suddenly switches to full screen, and this pops up.

If I run it at a smaller resolution, this doesn’t happen, but the UI won’t function. Any ideas how to fix this?

Never mind, I just fixed it. I created a new panel for my main menu and transferred everything into it. The menu is set up exactly the same way, but for some reason it works now. Oh well.