GUI not appearing in exported game

I have a very simple main menu set up. In Unity's built in player it appears and works as intended. However, when I export to nothing appears for the main scene except the default blue background used in Unities launching screen. Tapping the screen where the button should be to launch the main games scene and the GUI elements and the like appear and function correctly.

However, trying to launch the main menu again crashes the application, which doesn't happen in unities default launcher.

My scene contains only an Event System, some images, and some text (some used as buttons, others used as pure decoration). Exporting for windows functions correctly as well.

Any guidance/help is much appreciated.