Screen black after loading a specific level (Packaged Game)

We have a little problem with our project. If we play the game in the editor, there’s no problem. However, the screen turns completely black after we load a certain level. When we return to the main menu, everything is still black. Only the user interface is visible.

Has anyone had similar problems and knows the solution?

Thank you in advance!

Best regards

I fixed the problem. When loading the new level, a widget is created that slowly darkens the screen. This widget remains in existence when the new level is loaded and must be removed manually. This is only the case if you play the game in Standalone Mode or if you have packaged it.