The game load in normal play but it's not working when launch the game in unreal engine 4

hello I making a game using Blueprints and some C++ actor together to do some functions … and it’s going well when I test it in normal Play in Level editor and no problem with it but when I trying to export the game and Run it or Click Launch The level from UE4 editor the Level it’s Not Loading and it keeps resting and send me back to the last level ?