scene loading problem when it's loading second time.

Hello,

I am making an action game. I have added pause menu and several buttons like 'options' and 'return to the main menu'. Here is the problem when I am starting the new game the scene is getting loaded correctly but when I am going back to the main menu (from pause menu options->return to the main menu) and starting new game again the whole game getting stuck.

I am unable to find what is the problem.. My scene is having intractable and animated assets, particles systems, enemies, player and UI.

Please help...

Thanks in advance..