Hello :), I created an endless game style game, it worked on my laptop then I changed the name of my project to UE4 and when I put the game back on my laptop I had a problem with the gameplay , screen bug, loss of fps, I don’t know what can cause this :(, I made a video to show you, can you help me please? 
https://youtu.be/RfMz_0Ucggs Thank you.
(i’m french sorry for my english :o)