I tried different things. I have just one level with one level blueprints and different other blueprints for my actors, widgets and so on. I tried to call the spawn from a custom event of another blueprint (like you suggested), but the problem is the same. The Cube spawns in the viewport window but not in the level. I can’t even select or delete it. Finally i have chosen a completely different way to reach my goals. However it would be interessting to understand the issue, so if someone has further ideas, it would try them.