Dose Resolution Switch In Game Works

I am trying to change the resolution in my game.

I want may game to start on a given resolution defined in Script and after that Change it as per user input,
But when i do that my screen just go black and nothing happen a prat from the size of my windowed game changes But no visuals can be seen.
I have been searching for this but i am not been able to find a solution for what i am experiencing, everything just stuck and i dose not move at all