That's a generic enough issue that I don't know what the cause would be off the top of my head. Are there any errors in chat? Did you try pausing/unpausing? Can you send me a screenshot or video of what happens?
When I pause the game goes back to normal, but when I unpause the brown screen comes back. This error appeared, I uninstalled the mod and installed it again but still the same thing.
Oh, this is a bug I still need to fix, there's a setting that is currently broken - go to %localappdata%/nuclearthrone/data and destroy the NT3D.mod directory, and it should fix itself