Unfixable error

Hi, I'm currently working on a drinking game for mobile phones, everything was going smoothly (as smooth as you would expect gamedev to be) Today I came across an error that occurs at start. It's the usual, nullreference: Object reference not set to an instance of an object. Normally you would click on it, assign the variable and done, the issue starts here. Whenever I click on it, nothing happens. I've checked every little variable, everything should work. I haven't changed anything and it just happened out of nowhere. I've tried updating Visual studio, reimporting all assets. Nothing works. It makes my game freeze. Please help me out on this one.

,Hi, I'm currently working on a drinking game, the only thing is. Today I came across an error that freezes my game, it should be an easy error to fix "NullReferenceException: Object reference not set to an instance of an object. Normally you would just click on it, assign a reference, but the problem is. Whenever I click on it, nothing happens, it doesn't show me anything. The strangest thing is, I haven't changed anything, everything worked but out of nowhere it stopped. I've checked every little variable I have, everything is assigned as it should be, please help me out on thhis one. The error occurs at start.