My app stops in Simulator

The code is good and does not show any error. 

No, the code may compile and build an app but not be good.
But, without getting more precise information, and without seeing code, very hard to say.

Is it a SwiftUI or a UIKit app ?

At least, post the Swift AppDelegate file and the Swift SceneDelegate file.
Could you post the project somewhere or provide an email address to allow to share files ?

the app stops working or displays a black screen.

When the app starts before stopping, what do you get ?
Have you a launch screen, do you see it before app turning black ?

lemme guess, you didn't connect the view controller to your storyboard reference, then set root view controller and the is initial view controller...

recommendation, learn to build a basic app from iOS academy, then work on your own apps

I use SwiftiUi. I started to create my application in main.storyboard. I inserted some text, some images.
My application is starting to take shape, I wanted to open it to see how it looks like. I haven't touched the other files Appdelegate, SceneDelegate.

And when I open the application in the simulator, the screen goes black and then a few minutes later, it stops. The application bugs, but why?

If you use SwiftUI, you should not need a storyboard, except for the launchScreen.

I don't really understand your setup.

Hello, I made a mistake in the project. I forgot to put the images in Assets.xcassets and I modified info.plist.
I used UIkit, not SwiftUI.
Sorry

Problem was effectively in launchScreen ? So it is solved now ?

Don't forget to close the thread on the correct answer.