I am using Spritemanager 2 to manage my 2d GUI elements. I had my UI Camera set to perspective mode and everything was working great. I put changed it to Orthographic mode, and it works perfect again in the editor, but when I build the game, this camera doesn't show up at all. It doesn't display anything, even if I set the culling mask to everything, but again works perfect in the editor. Any ideas anyone?
Solved, as it turns out, you MUST have at least depth selected on clear flags when stacking an orthographic camera on top of a perspective one. I don't know why, or if this is a bug, but that fixed it for me.