My geometry box just disappeared

Hello everyone,
I’m a complete beginner on UE4, i started yesterday since i bought a course Epic Games approved on Udemy and i just did few lessons for now,
I was trying to make the floor like on my lesson so i put a geometry box and i wanted to switch perspective to put my box exactly in the middle, but i missclicked and i clicked on lit and i did something and my geometry box just disappeared, i can still click on my box and i can see the form but i can’t see it anymore when i unclick it, except if i change from Lit to Unlit,
Yesterday when i wanted to restart the Unreal Engine to keep doing my level, i had the same problem, everything turned to black, this time i didn’t click on Lit or anything, so since i was only on few video on my tutorial and this was not covered yet, i deleted and installed again UE4, but this is clearly not the solution,
here are few screens on


, if anyone can explain me the problem and tell me how to resolve it, it would be nice
Thank you :slight_smile: