Question (Thread in the right spot?) Using prefab UI from other scenes

So I got this ui for a menu called "menu", i liked everything back through on the canvas, and there is no script error but the ui doesn't appear. On the other level it does, but this one just pauses the game, and there is no ui popping up so it looks like it froze unless u click esc again then it 'unpauses'
I'm not sure what I did wrong it worked on all my other 6 scenes.